Daffodil - I have a friend who is a keen Munro Bagger and who would also highly recommend "The Munros: Scottish Mountaineering Club Hillwalkers Guide" as suggest by Pookie.
Cameron McNeish has a similar book but according to my friend it's not as good as the SMC one.
Incidently, he was upset recently to find that one of the Munros he had bagged is now classified as a Corbett.