Wonderful insight into financial modeling by Glenn Kelman @ Redfin.
http://blog.guykawasaki.com/2007/10/financial-model.html
"...When first putting together our financial model, we looked online to calibrate spending assumptions. So many people have blown venture capital, we thought, there must be a manual somewhere on how to do it, at what rate, avoiding which follies. We couldn’t find anything. So we took some wild guesses and figured we’d see how they turned out. And now two years later to the day that we built our first model, here are the projections and actual results. Hopefully, you can learn from our experiences..."