"Starting Something" - The story of Neoforma, from startup to IPO, written by one of the two founders. Has especially great insights on the people aspect of the journey (VC's, employees, family, partners, angel investors...etc).
'The Search' - talks about Google and search companies in general, how they started, how they developed their business model, and the evolution of the industry in general. Especially fascinating is Bill Gross's story, and how he started ToGo.com (later became Overture) and invented a lot of the things that people commonly only associate with Google. It was also the first time I read the in-depth story about the founding of Google. inspiring...
'Founders at Work' is terrific also. Can't wait for the second part.
I'll throw in an extra recommendation. Not exactly a book, but a podcast actually. It's called "Venture Voice". It a series of interviews with entrepreneurs (Ev Williams of Twitter/Blogger/Odeo, Jay Adelson of Revision 3 and CEO of Digg, Calicanis of Weblogs Inc, Kawasaki, Mena Trott of Six Apart, to name a few). You can think of it as an audio version of 'Founders at Work'. Those two are a real must especially for web entrepreneurs.