If you've never called coyotes before, I'd suggest buying a predator calling dvd and listen to the sounds and cadence of the sounds so that you have an idea of what you need to sound like, especially if you'll be using hand calls. There's not a hand call made that won't call a coyote, but some are better than others. If you'll be using an electronic call, try about any distress sound that it has. Sit in one spot and call off and on for at least 15 minutes, and longer if you get a vocal response from a coyote. Get in a spot where you can see any approaching coyotes, and kill'em before they smell you.
In the winter, I call all day long every chance I get because they will respond at all times of the day. In warmer temps. during spring/summer, mornings and evenings will be your best bet because they won't be nearly as active during mid day.
I don't mess with a decoy for the most part. A decoy is a piece of gear that's simply extra weight. It might help sometimes, but it'll spook'em sometimes too.