I'm about to write a business plan. Where should I start?
pedalpete: I like to start with an introduction of what you are going to accomplish. No more than one page, hopefully only 1/2 page.
Then a SWOT. 
Then a SlideDeck (I use Prezi.com).I wouldn't go down the road of a proper 'business plan' unless you are going to a bank for a loan. You won't follow it, and you won't up date it.Get the basics down, and then go from there.Assume that even what you create won't be seen by anybody else. It is often more of a guide for yourself (depending on your situation/organization of course).