Iron Man: My Journey through Heaven and Hell with Black Sabbath
The book is an easy read, though the 90 chapters of approximately equal (short) length tend to make all the events appear a bit too even in importance or significance. Also, these chapters are supposed to be in chronological order, but there are several incoherences. With a little thought, you can recover what's going on, but these issues should have been handled more carefully by the co-writer T.J. Lammers (I assume he's a professional writer). Overall, it reads too much like an extended journal interview.
However, these were not big issues for me. I was more disappointed by the fact that Tony, as he himself admits, isn't a very oustpoken guy, and you'd expect a little bit more from an autobiography. Tony may be precise about a given subject, but often you don't get much of his underlying motivation, and of his emotions. When it comes to people, it depends strikingly on whom he's talking about: for example, Bill Ward's misfortunes and oddities are so fully depicted that he comes across as both a miraculous survivor and a total loony, but you'll be hard-pressed to find anything not politically correct about the Osbournes. There are, at most, allusions: for instance, to Sharon dropping Lita Ford (anyway, "Lovely Lita" doesn't get much room: less than 2 pages...). In fact, a non-negligible part of the end of the book, starting with the "Ozzy will always be my friend" bit, sounds to me like timely preparations and marketing for the announcement of the forthcoming Black Sabbath reunion.
I enjoyed reading the book nonetheless, and I'm sure most Iommi fans will enjoy it as well. But at the end of the day, I don't think I gained much insight into the man himself.