for you do it yourselfers - my wife found a great book we've used the last couple of years for her art & framing business and my IM titled "Minding Her Own Business" by Jan Zobel. she briefly talks about it in a recent blog post:
Tax Time
i believe she is going to do a followup post at some point and break it down in the future for more detailed tax explanations. although the book is marketed towards women (HER OWN), it's really applicable to anyone.