Woody,
Check out Predatormasters.com. That is a site all about predator hunting, you should be able to get lots of good info on your topic. There are many professional coyote hunters there and many of the call makers there as well, great site.
You got some good responses here as well, but if you are looking for more you may want to check it out.

If you have never called coyotes before don' t get discouraged if it turns out to be a little tougher than you may have imagined. Stay at it and they will come in eventually. If you have then you know the challenge you are in for with the bow.

Calling coyotes in to the bow should be interesting, like the previous posters said you will need to set up a distraction (decoy maybe) or use cover to cover your movement. It is amazing how fast a coyote picks up movement.