Well, I'm a fan of Hizzoner, St. Shepard of Monogram, and feel that if you only buy ONE book about building dioramas, it'd better be his... After all, he's the guy that made the diorama what it is to most of us who grew up with Mongram in the 70s and he was also my inspiration in becoming a "serious" modeler and diorama builder... Whether or not you like his work or not is moot, the techniques he used and many cases, pioneered, have inspired at least two generations of Dio-builders, and continue to do so...
Here's a link to more of Shep's work, some familiar, some not so...
http://sheperdpaine.com/index.htm