You can probably find someone that you know that waterfowl hunts and the best way to learn would be to hook up with them to start out. If you don't know anyone, try to find someone.
Check out the refuge forums,
www.refugeforums.com and check out your states board and start talking to people.
In either case, get as many decoys as you an afford at first, usually just a few dozen will work, and learn the techniques of duck hunting.
Start learning to call now, as that is a greater skill and tool than decoys, and work on it all year. Just to prove my point, we were packing up and about ready to go the other day at the end of a hunt when a flock of mallards came down the lake looking for somewhere to go. I was standing next to the boat and it was uncovered and we were both out in the open, but I pulled my call back out and started on them and they came our way. I figured they would flare off, but they came close enough and my uncle killed the closest greenhead. I was amazed, as this rarely happens, but they came right to the calling.
Good luck.