Well, I don't know any reference that examines ''each nook and corner'', but as Kevin says in a comment above, Washington's ''Cyclotomic fields'' is one good place to start (assuming you have enough grounding in algebraic number theory).

In addition, Lang's ''Algebraic number theory'' contains some things on class number formulas I think; also we have his two-volume (now as one-volume at Springer) book(s) on Cyclotomic fields. But beware, I would say that these/this require a firmer background, than Washington's book.

(Without encouraging illegal activities, I'm sure there are some bootleg versions on the net of the above books.)

Otherwise, there are dozens of nice books on the subject. Also, there must be tonnes of free lecture notes out there in cyberspace.

Number fields, which contains a proof of the class number formula. $\endgroup$ – François Brunault Jul 5 '11 at 18:45