Altars can be indoors or outdoors, in any room, field, or forest you desire. Keep in mind that when placing the altar indoors, it should be in a safe place where you can light candles and other items without being in danger of setting fire to anything (such as the drapes).  Remember that your altar is a part of your sacred space, and it should be treated with respect. It is probably a bad idea to put it in a high-traffic area, or a place that will make it difficult for you to enter the state of mind necessary to work magick. The bedroom is often a good choice, or another room that isn't used often (the guest room, an extra living room, etc.). Be careful when placing the altar in the bedroom, however - this room is associated with sleep, and if you work magick while you're tired, you're more likely to fall asleep.

    The altar is usually placed facing north or east. By "facing north or east," I mean that the objects are set onto the altar in such a way so that while working the altar, you are facing either north or east. You can, of course, face it any direction, but north and east are traditional for various reasons. The north is correlated with the Earth, with strength and calm and steadfastness - this can be useful when performing magick by keeping your energy grounded and focused. The east is correlated with air, thought, intuition, and inspiration - this can be useful when working by focusing your mind on the task at hand, and minimizing distractions. East is also the direction of the rising sun and, therefore, new beginnings - magick is always designed to cause change and, therefore, new beginnings, so facing the altar east is appropriate. If you can easily adjust your altar, you can face it in different directions each time you work (depending on which direction's energy corresponds most to the work you perform). However, stability and routine produce powerful triggers for releasing your own personal power, and constant change may be counterproductive in this sense. Basically, experiment, and find what works best for you.

   The altar is placed in the center of the circle, although space limitations may dictate otherwise. It is preferable to be able to walk around the altar easily, which is an important part of creating sacred space and casting the circle. If you don't have enough room, don't worry about it. You can place the altar against the wall and create the circle from within, using yourself as the center (and drawing the circle large enough to keep the altar inside).