One word of caution regarding CDs and such...
I have a very good friend who is an accomplished waterfowler tell me last year when I was hot on the "gotta learn it all" trail in regards to short reed goose calls..."learn to do three things...cluck, moan, and honk...so much that you can pick up the call and without even thinking about it much and make those sounds...because in a hunting situation you don't always have the time to work your way up to a particular sound..." I argued with him a bit, and insisted on being able to run quick-spits, regular spit-notes, and sexy little comebacks...and he would just laugh...
When we hunted together last year, I would often find him walking over the top of my spit-note efforts with rapid clucking and moans...I got the point. Not to say those notes are not effective...it's just that honks, clucks, and moans will kill geese...flat out.
His opinion is that guys put WAY too much into the practice of "competition-type" calling...and to some extent I agree. For sure there are times when you need to run the gamet of sounds (i.e. Todd Farm) to get their attention, but for the most part...you want to sound like a contented animal that is letting approaching birds know that everything is safe down here....or that "this food is mine...so stay out..." in some situations. For the most part, in regards to goose calling...all of the sounds are based off of the honk and the moan...so master those two and go from there.
I have CD's from Dave Smith, Quacker Attacker, and Threinen...and they are all very good...each in their own way. I practice my calling a lot, and have come a long ways over the last two years. I think the guys that post on here that I have hunted with will acknowledge that fact, but there are still times when I struggle, and for that I keep on working on it. Being flawless and sounding realistic is what you want...
Duck calling??? Well...to each his own. I own a bunch of calls, and there are times when I feel that they work (i.e. field hunting) but in the marsh...where there is competition, sometimes the deadliest call is the one that stays in the blind bag.
Hope that helps...and don't hesitate to send a PM to Smoke or any of the other sponsors here...they are all knowledgeable and willing to help if they can.