Following are some books on aquaponics:
Aquaponic Gardening – First book I read. Great introductory guide to aquaponics.
The Idiot’s Guide to Aquaponics – If you’re familiar with this series, this is more of the same. Very broad discussion but not very deep in any one area.
Aquaponic Food Production – Book on on commercial aquponics systems by Nelson & Pade. Good discussion of their methods, though limited.
Urban Aquponics Manual – First ever book on aquaponics available online only.
Feel free to post additional books in the comments section below. If they seem legit’, I’ll add them to the list.