Founder Dilution - How Much Is "Normal"?
http://www.avc.com/a_vc/2009/02/founder-dilution-how-much-is-normal.html

This is a subject near and dear to entrepreneurs, maybe the dearest subject of them all. Founders start out with 100% of the company and every time they raise capital and/or issue stock and options to their management team, that number goes down.