Ask HN: Business plan... what do you include in it?

I assume a good portion of the visitors to this site are entrepreneurs. I am not, ... not yet at least. Assuming that you use some type of document to sync up vision & goals between your initial partners, what do you include in that document for these first critical discussions? What are the most important things to take into consideration?

Also, if you feel comfortable, it would be a great help to see some samples of ones you've written in the past.