Hi Davidh
It seems that Klingon is an art language like Esperaoto, IDO, Volapyk, Lojban, The Tolkien Languages or, or , or....
Klingon was made in connection to Star Trek by Marc Okrand.
He later published a book called: "The Klingon Dictionary".
It is still to be bought so if you really are interested you will
read your fill in that book. From what I found the book contains:
"an introduction to Klingon phonology, morphology, and syntax, with little bits of pragmatics and sociolinguistic thrown in."
The books full data is:
Title: The Klingon Dictionary
Author: Marc Okrand
Publisher: Pocket Books / Simon & Schuster Inc.
Year of Publication: 1992
ISBN: 0-671-74559-X
Marc Okrand has written quite a number of books related to this subject it seems so they must sell well :)
This means of course that The Klingon Dictionary is not the only book on Klingon.
As a last remark I found these links for you. Both will probably interest you. Happy reading!
The Klingon Language Institute.
http://www.kli.org/
The Klingon Language Faq
http://www.softlab.ece.ntua.gr/miscellaneous/faq/klingon_language_faq.html