"Catholicism is not a reality that stands by itself." writes Richard McBrien in his famous summa Catholicism. "The word Catholic is not only a noun but an adjective. As an adjective it is a qualification of Christian, just as Christian is a qualification of religious, and religious is a qualification of human. Thus, Catholicism refers to a community of persons (the human dimension), who believe in God and shape their lives according to that belief (the religious dimension), who believe that God to be triune, and Jesus Christ to be the Son of God and the redeemer of humankind (the Christian dimension), who express and celebrate that belief in the Eucharist and who recognize the bishop of Rome to be 'the perpetual and visible source and foundation of the unity of the bishops and of the multitude of the faithful' [Dogmatic Constitution on the Church, n. 23] (the ecclesial dimension). To be Catholic, therefore, is to be a kind of human being, a kind of religious person, and a kind of Christian belonging to a specific eucharistic faith community within the worldwide, or ecumenical, Body of Christ. To be Catholic is, before all else, to be human." McBrien, Richard. Catholicism. p. 6.

The word "catholic" comes from the greek katholikos, which simply means "universal." It is believed that the first time the word was used to describe the Church that Christ founded was in A.D. 114, by St. Ignatius of Antioch.

The Nicene Creed, adopted in A.D. 325 gives a good summary of what Catholics believe. The creed follows below. My comments are in italics:

"We believe in one God, the Father, the Almighty, maker of heaven and earth, of all things, seen and unseen."
Catholics believe in an all-powerful, omnipotent, loving, merciful, creator God.

"We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God from God, Light from Light, true God from true God, begotten, not made, one in Being with the Father. Through Him all things were made. For us and for our salvation He came down from heaven:"
God loved the world so much, He sent His Son to the Earth to save humanity from sin and death.

"By the power of the Holy Spirit he was born of the Virgin Mary, and became man."
This is called the Incarnation...we believe that Jesus was truly human and truly God.

"For our sake, He was crucified under Pontius Pilate; he suffered, died, and was buried."
Christ died on the cross to redeem humanity; that is, to make it possible for all people to be saved (go to heaven).

"On the third day, he rose again in fulfillment of the Scriptures;"
Christ defeated death forever by rising in triumph. Today, this celebration is called Easter. It is the most important feast of the Christian year.

"He ascended into heaven and is seated at the right hand of the Father. He will come again in glory to judge the living and the dead, and his kingdom will have no end."
The 12 apostles, the original followers of Christ, witnessed his ascension in to heaven.

"We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son. With the Father and the Son he is worshiped and glorified. He has spoken through the Prophets."
The Holy Spirit is the third person of the Holy Trinity. Catholics believe in One God in three persons.

"We believe in one holy catholic and apostolic Church."
Christ's Church is holy, universal, and authoritative.

"We acknowledge one baptism for the forgiveness of sins."
Most Catholics are baptized when they are infants.

"We look for the resurrection of the dead, and the life of the world to come. Amen." When Christ returns in glory at the end of the world, our souls will be reunited with our bodies, and we will enjoy eternal life.

There are many churches that are Christian, but not Catholic. Because of this, it is proper to say "The Roman Catholic Church" to refer specifically to that body of Christians who acknowledge the authority of the bishop of Rome as the supreme pastor of the Church. The Roman Catholic Church, however, calls itself simply "The Catholic Church," which simply means "the universal church."

Put simply, the Catholic Church is the universal body of believers in Jesus Christ on Earth.

Yes. All Roman Catholics are Christians, but not all Christians are Catholics (with a capital C).

Jesus Christ instituted His Church, which is "born primarily of Christ's total self-giving for our salvation, anticipated in the Eucharist and fulfilled on the Cross." (CCC 766) "The Lord Jesus inaugurated his Church by preaching the Good News, that is, the coming of the Reign of God, promised over the ages in the Scriptures." (Lumen Gentium 5)

The Catholic Old Testament, which contains 46 books, is based on the Alexandrian Canon, or Septuagint. The Septuagint is the product of work done in Alexandria Egypt during the reign of Ptolemy II Philadelphus (285-246 B.C.) to translate the entire Hebrew Bible in to Greek. The work was conducted by 70 or 72 Jewish Scholars, six from each of the 12 tribes of Israel (by tradition), hence the name "Septuagint" which is Latin for 70. When it was completed, the Septuagint was very popular because Greek was the common language of the entire Mediterranean world by the time of Christ. Christ and all of the New Testament writers used the Septuagint. (Remember that the entire New Testament was written in Greek. It is no surprise that when the question of which canon to adopt came before the Church as its universal standard for the Old Testament texts, the Alexandrian Canon was authorized and defined as scriptural. It is more correct to say that Protestant Bibles use less books than the Catholic Bible does because in 1529, Martin Luther advocated use of the Palestinian, or Hebrew, Canon of the Old Testament, which contains 39 books. This Hebrew Canon was established by Jewish rabbis at the Council of Jamnia around A.D. 100. It is thought that this canon was possibly developed in reaction to the Christian Church, which was using the Alexandrian Canon. The Jews at Jamnia rejected seven books that were found in the Septuagint (Alexandrian Canon): Wisdom, Sirach, Judith, Baruch, Tobit, and 1 and 2 Maccabees (as well as portions of Daniel and Esther) because they could not find any versions of these books that were written in Hebrew. Specifically, the Council of Jamnia used four criteria to determine their canon. They accepted only books which were: 1) written in Hebrew; 2) in conformity with the Torah; 3) older than the time of Ezra (c. 400 B.C.); 4) written in Palestine. Catholics use the Alexandrian Canon of the Bible because it was the canon used by Jesus Christ, the New Testament writers, and the early Church, not the canon used by the Jews who rejected Christ and persecuted Christians.

Contrary to the belief of many non-Catholics, the Bible did not just "fall out of the sky," and it is not the product of any single individual. As the Christian Church began to expand in the first and second centuries, bishops in major churches began to collect documents that they felt were profitable for the instruction of the members in their congregations. The universal use of the Old Testament Scriptures, as well as the Gospels of Matthew, Mark, Luke, and John, is known to have been the major unifying element of the early diocesan canons which began to be developed by various bishops. Besides these items, there was no universal agreement about what other documents should be used to instruct the faithful. Bishops in different regions had different concerns, and they were geographically separated from each other. As bishops would communicate with their brethren in other cities, they would do so by writing letters. Over time, the letters built up, and the value of these letters came to be recognized. Some bishops began employing them for use in their churches to assist in Christian instruction. The letters and documents used by one bishop in one church could differ significantly from the letters and documents used by the bishop in the next city. Seeing the expansion of the Church in the 4th century under the Peace of Constantine, Pope St. Damasus realized the need to develop a canon of sacred scripture for the universal church of Christ, to be used by all Christian Churches everywhere. In 382, he summoned several bishops to a synod in Rome to decide which letters and documents would be authorized for use in the Church. There was vigorous debate. Some bishops questioned the authenticity of various documents, and there was much disagreement about which specific works should be included in a final canon. However, an agreement was finally reached at the synod, and the first document containing our present canon of scripture was produced. This listing of books was subsequently authorized at the larger Councils of Carthage (A.D. 397) and Hippo (A.D. 393). The Canon of the Bible was defined and authorized by the Catholic Church, under a Catholic pope. The canon defined in 382 remained un-molested by the Christian community for some 1,100 years, until Protestant Reformers in the 16th century saw fit to adopt a different canon of the Old Testament.

The pope is the Supreme Pastor of the Catholic Church. He is the vicar of Christ, the leader of the Church on Earth. His titles include the "Servant of the Servants of God," and the "Bishop of Rome." The pope is not divine (he is not God).

St. Peter was the first pope. We believe that Christ made Peter the first pope in the Gospel of St. Matthew, chapter 16, verses 18-20. "And I (Jesus) say to you: you are Peter, the Rock; and on this rock I will build my church, and the powers of death shall never conquer it. I will give you the keys of the kingdom of Heaven; what you forbid on earth shall be forbidden in heaven, and what you allow on earth shall be allowed in heaven."

"Throughout the Gospels, St. Peter is unmistakably the leader of the Apostles. Peter often spoke for the rest of the Apostles (Mt. 19:27, Mk 8:29, Lk 12:41, Jn 6:69). The Apostles are sometimes referred to as "Peter and his companions" (Lk 9:32; Mk 16:7; Acts 2:37). Peter's name always heads the list of the Apostles (Mt 10:1-4; Mk 3:16-19; Lk 6:14-16; Acts 1:13). Finally, Peter's name is mentioned 191 times, which is more than all the rest of the Apostles combined (about 130 times). After Peter, the most frequently mentioned Apostle is John, whose name appears 48 times.

Peter is conspicuously involved in all of the Church's "firsts." Peter led the meeting which elected the first successor to an Apostle (Acts 1:13-26). Peter preached the first sermon at Pentecost (Acts 2:14). Peter performed the first miracle after Pentecost (Acts 3:6-7), inflicted the first punishment against Ananias and Saphira (Acts 5:1-11), and excommunicated the first heretic, Simon the magician (Acts 8:21). Peter is the first Apostle to raise a person from the dead (Acts 9:36-41). Peter, not Paul, first received the revelation to admit Gentiles into the Church (Acts 10:9-16), and commanded that the first Gentile converts be baptized (Acts 10:44-48)." Fr. Frank Chacon and Jim Burnham, Beginning Apologetics I

This is because the Church pre-dates the existence of the Bible. The books of the New Testament didn't even begin to be written down until long after the Church was instituted by Christ, who died around A.D. 33. The earliest New Testament document is the Gospel of Mark, written down around A.D. 60, some 30 years after Christ's death, with the last being completed by around A.D. 110. How could the Bible be the "sole rule of faith" for the Christian Church, if the current texts were not even completed until some 70-80 years after the Church came in to existence?

Moreover, just because the documents were in existence, does not mean that they were regarded as Scripture. In fact, it wasn't until the late 4th century that anything close to our modern day idea of a "Bible" even came in to existence, and then because of the Church. (see question 8 above)

In general, Yes. Catholicism is not a cafeteria religion where you can pick and choose the doctrines that you agree with.