Of the ones that are still relatively easy to find (and inexpensively so), I'd recommend Mick's book, first and foremost. It might not be wholly accurate, but at least it's an insider's account.
Bob Brunning's book is also pretty good, and is interesting because of his status as a former Mac member & insider.
The Leah Furman book isn't awful, though it's really nothing more than a summation of the information and interviews that can be found here on the Blue Letter Archives. But if you're looking for some particular piece of information, and you're not near a computer, it can come in handy.
The 'Authorized History' book that David mentioned (which was actually written by Samuel Graham, not Sam Emerson
), is great, but it's outdated by 26 years, and can be pretty hard to track down.