Below is a link to 6 minutes of sound advice from a tax attorney who works with photographers. It's produced by Photoshelter and is posted on the PhotoShelter blog.
This is the link: Expenses and Red Flags: Interview with the Tax Ninja
The most important thing to take away from this ... document everything and save all receipts.
What would 6 minutes of advice from a top attorney cost? Maybe $25- 35. Click on the link and save some money.