I would like to know what the difference between a pedagogical grammar and a reference grammar is. How can I get more information about a reference grammar?
Two good examples of pedagogical grammars are,
The Grammar Book: An ESL/EFL Teacher's Course, Second Edition by Marianne Celce-Murcia and Diane Larsen-Freeman
Amazon.com: The Grammar Book Murcia: Books
Longman Language Activator: Helps You Write and Speak Natural English, Second Edition
Amazon.com: Longman language activator: Books
This one isn't really a grammar. It's a special type of dictionary meant to expand a student's vocabulary and in this it has, IMO, no equal.
A couple of good examples of reference grammars are,
The Cambridge Grammar of the English Language
The Cambridge Grammar of the English Language by Rodney D. Huddleston and Geoffrey K. Pullum
Amazon.com: Cambridge grammar of the English: Books
Hardcover, Longman Grammar of Spoken and Written English
Hardcover, Longman Grammar of Spoken and Written English by Douglas Biber, Stig Johansson, Geoffrey Leech, and Susan Conrad
Amazon.com: Longman grammar of spoken: Books