Where can I find more information about Ars Magica?

Ars Magica has an active community and a large number of supporters on the web. A good place to start is the web site for the line, Atlas Games. There is also a very active mailing list. Several fan magazines have been published and are still being published, and there are a number of web sites devoted to the game and individual players' sagas. Finally, there is a list of suggested reading material available if you would like to research on your own.