Hi.
I was wondering what is the best book on open source that is a must read? I was thinking of getting 'The Cathedral and the Bazaar' but I thought I had check once with you guys here.
I am interested in general books about open source and how open source works.
You can read 'The Cathedral and the Bazaar' online at http://catb.org/esr/writings/cathedral-bazaar/. However, as from the question I suspect you haven't had much personal experience within the FLOSS community, I would suggest a better book to start with is probably Open Sources: Voices from the open source revolution.
Eric Raymond has his own particular take on open-source, and that will lead you astray if you read him without being aware of the other takes on open-source/free-software. Open Sources is a collection of essays by various key people who helped found, and cultivate, the FLOSS movements. Yes, ESR is there, but so are Linus Torvalds, Richard Stallman, Bruce Perens, and Bob Young, among others. If you want to understand something as diverse as open-source, you need to read something more diverse than CatB.
Oh, and eventually you will need to read CatB, as it is one of the seminal works on the topic—but probably not first.