Is there a site that anyone knows of where I can find info on the following about the language of a book:
informal/formal
diction
literary devices
By "language of a book" you mean, I think, the terminology of literature, the language we use to talk about writing. Diction concerns the choice of words to be used. Here is the closest I have come for a definition of literary device:
I hope that helps.a particular word pattern, figure of speech, combination of word sounds, etc., used in a literary work to evoke a desired effect or arouse a desired reaction in the reader: rhetorical devices.
http://www.infoplease.com/ipd/A0406001.html
Here's a glossary of literay terms:
http://www.virtualsalt.com/litterms.htm