Whole Dog Journal has an excellent article about this very subject and right now the subscription to the newsletter for one year is only $20.00 for 12 issues.
whole-dog-journal - Whole Dog Journal Subscription [Magazine-Agent.com]
I highly recommend this newsletter for anyone but if you have the $20.00 and can sign up right away I think you can go on-line and read the article and print it off. If not you can always get it in a back order..