There are lots of opinions on calls and callers, here is my 2c: I use the Haydel VTM 90 which is basically a DR-85 with a hole in the barrel. My buddy who was is a trumpet player in high school has great breath control. He uses a Yentzen Mod 500 (made in Grooves, Texas) and he can hypnotize the greenheads. I never could master the Yentzen, it's not for beginners. I would suggest getting a good whistle, I like Haydels MP-90. I can't make it sing like Ron and Eli can, but you are not very likely to flare ducks with a whistle while you are learning. Lastly, get a teal call ,BT-85, is what I use. It's not the easiest call to blow but the first time you turn a bunch of teal you'll be hooked. You can get so involved in the calling that you you're late on the shooting part. Welcome to your latest passion!
http://www.haydels.com has some good audio tips on calling. I'll admit that I am not very good at spec calling. My buds that are addicts use a Redbone spec call and stuffer decoys.
http://www.redbonecalls.com These are extravagantly expensive but they are the ultimate. It's worthwhile to visit their website. Even Nate Wright admits that the key to consistently killing specs is location, location, location. It doesn't matter how good you are at calling if they aren't using the field, your results will be spotty at best. Get some yourself some calls, practice, and enjoy.