I highly recommend the Lyman Shotshell Reloading Handbook 4th edition manual. Also try powder manufacturers websites such as Winchester and Hodgdon and others. As Jim said, use "exactly" the components listed in the manual. I like Winchester Super Field powder for up to 1 1/4 oz. hunting loads using 4-5-6-or 7 1/2 shot. Give the Hodgdon web site a look: http://www.hodgdon.com/data/shotshel/index.php
The Hodgdon Longshot powder would make a good heavy hunting load. You will probably want #2 or BB sized shot for your coyotes.
Get all the literature on shotshell reloading that you can and follow the recipes exactly.