Listmania!
The Caucasus
Georgia with Armenia (The Bradt Travel Guide)Georgia with Armenia (The Bradt Travel Guide) by Tim Buford
Buy used from: £0.99
Bradt guides are one of the best series of guidebooks available and this one is a good buy!
Azerbaijan: With Excursions to Georgia (Trailblazer)Azerbaijan: With Excursions to Georgia (Trailblazer) by Mark Elliott
Buy used from: £19.99
The best (only?) guidebook to Azerbaijan, with an excellent section on Georgia. Also, one of the best guidebooks that I have ever used "in the field".
Georgia, Armenia and Azerbaijan (Lonely Planet Country Guide)Georgia, Armenia and Azerbaijan (Lonely Planet Country Guide) by Neil Wilson
Buy used from: £0.46
Lonely Planet's guidebook is not one of the best, but could be a useful primer.
Georgian-English/English-Georgian Dictionary and Phrasebook (Hippocrene dictionary & phrasebook series)Georgian-English/English-Georgian Dictionary and Phrasebook (Hippocrene dictionary & phrasebook series) by Nicholas Awde
Buy used from: £155.69
Learn the language!
Azerbaijani-English, English-Azerbaijani Dictionary and Phrasebook: Spoken in Azerbaijan and Iran (Hippocrene Dictionary & Phrasebook)Azerbaijani-English, English-Azerbaijani Dictionary and Phrasebook: Spoken in Azerbaijan and Iran (Hippocrene Dictionary & Phrasebook) by Nicholas Awde
Buy new: £8.99 / Used from: £5.29
And, while you're at it, learn some Azerbaijani too...
The Spirit-WrestlersThe Spirit-Wrestlers by Philip Marsden
Buy new: £5.49 / Used from: £0.01
Philip Marsden is a superb writer on the Caucasus - he evokes the region perfectly.
The Crossing Place: Journey Among the ArmeniansThe Crossing Place: Journey Among the Armenians by Philip Marsden
Buy new: £5.65 / Used from: £0.50
A fascinating book about the Armenians.
The Georgian Feast: The Vibrant Culture and Savory Food of the Republic of GeorgiaThe Georgian Feast: The Vibrant Culture and Savory Food of the Republic of Georgia by D Goldstein
Buy new: £10.85 / Used from: £9.55
When you get back home, start making your own khachapuri!