For a concise introduction to many of the issues discussed on this site we also recommend 'Is Astrolology Divination - and Does it Matter?' by Geoffrey Cornelius.
For a survey of the variety of astrological experience, and perspectives thereon, from both astrologers and their critics: Astrology in the Year Zero by Garry Phillipson (London: Flare, 2000).
The full argument for regarding astrology as primarily a form of divination is in: The Moment of Astrology - Origins in Divination (2nd edn.) by Geoffrey Cornelius (Bournemouth: Wessex Astrologer, 2003).