Brittany travel resources:
books and maps
The "Rough Guide Brittany Map" (Amazon) was an excellent resource, covering the entire region at 1:200000 scale and marking places of interest as well as settlements and roads. It's printed on plastic paper, which helped with rain and wear and tear.
We had the 2004 Lonely Planet Brittany and Normandy Guide (Amazon) and the newer (May 2007) Rough Guide (Amazon UK). Both of us thought the Lonely Planet was much better, apart from some unreliability from being three years out of date.
For broader reading about Brittany, see my Brittany reading notes.