If you do a little searching, you should come up with one of the books threads that have come and gone. Generally though, Frank Brady's Citizen Welles is considered the best of the bunch, given its even-handedness toward its subject. The books by David Thomson and Charles Higham are the worst, at least in my opinion. Callow has some good points and some bad ones. Leaming is a fun read but not necessarily to be taken seriously in many cases.