Wow...what a book! I just finished reading Founders at Work and I've got to admit it's one of the best books I've read in the past several years. What makes it so special? It's a series of interviews with 32 different tech entrepreneurs, so it's like getting 32 mini-books in one. The book also has a nice mix of old and new technologies. For example, are you old enough to remember VisiCalc? If so, you'll enjoy the interview with Dan Bricklin.
You really get the feeling your sitting down with each one of the founders being interviewed. Great questions are asked throughout that help shed light on key turning points with each company, whether the founder ever wanted to give up, etc. You could argue that much of this information is probably available via magazine articles and online resources, but rather than having to gather it all up on your own, this book presents it all in one nice package. Highly recommended!