Teach Yourself Azeri
This is the most comprehensive Azeri grammar that I have found. It contains very useful exercises with an answer key and explains all of the basics of Azerbaijani grammar, including all verb tenses and moods. Its vocabulary and expressions are accurate. It is somewhat less user friendly than Öztopçu's book in that it assumes a certain familiarity with grammatical terms and moves rather briskly into very complicated grammar. I highly recommend this book for intermediate or advanced students, though it is unfortunately very difficult to find in the United States.