Which windows in my house are good for African violets?

North windows? West windows?

This is easy - put it somewhere in your house where you would be comfortable to spend your day. Somewhere with some air circulation but not in a draft, with good sunlight but not too strong (perhaps filtered by a sheer curtain) and not in darkness all day, with a comfortable temperature (15-25 deg C or 60-80 F). Fluorescent lights provide a good light source if natural light isn't sufficient.

What is important is that African violets do not like "hot" light, but do like bright light. To determine if your window is good for a violet, hold your hand in front of your window, palm down, on a sunny day. You should see a strong shadow from your hand, but you should not feel heat on the back of your hand. If you do feel heat, then make sure that a sheer curtain is drawn in front of the window.

With the advances in energy efficient window technology that have been made over the last few years, the above test is the best way to determine if your window is a good location for your plant. Some of the new high efficiency windows allow African violets to grow in south windows, where even ten years ago the heat would have killed the plant quickly. Make the test, and then watch your plant. It will let you know if it likes the new location.