The Lewis book is a very good one, with a lot of history/information. It's a bit flawed by being written in an academic style at times, though I didn't find it overly so. Hard to say whether it's a good book for a beginner. You might be introduced to names of musicians and to music you want check out, or you might be somewhat overwhelmed if you're unfamiliar with AACM.
I'd say that it can't hurt to try the book and then listen to some of the musicians discussed in it. You can always go back to the book when you're more familiar with the music and then it will probably have more meaning for you.