At present the IRS (as it appears after meeting with associates and actual audits) that the IRS Number One "Hit list" is the Schedule C. Therefore, I can only repeat that you keep good records (No, they do not have to be Computerized...but at least write them down and keep them in order). I am not a Bookkeeper, but will help you organize your records than will help you both understand the requirements and at the same time review your records to cut cost/expenses.
First most important thing, should you get any letters from the Internal Revenue Service (IRS) or Franchise Tax Board (FTB - California) is "OPEN IT AND READ IT< ASAP". If you do not understand it or just want to know how best to answer it, just give me call...this will cost you nothing, part of my services to you from Us. Looking forward to seeing you next year, perhaps sooner should the need arises.