As for your Choke 101 Class, I can teach you enough to where you can pass an elementary class. Mr. Clark Bush will chime in soon and he'll be able to have you pass the graduate course because he knows anything and everything about this subject. But I'll go ahead and start you off.
As for your Super Nova, that's a good gun choice and it'll make a fine turkey gun. I'm not sure what you mean when you asked for it to be a turkey gun so I'm not sure if they would add in a turkey choke for that or not. When I got my Benelli it came with 5 different choke tubes: Cylinder, Improved Cylinder, Modified, Improved Modified, and Full. I bought a separate choke for turkey hunting from Mr. Bush because it will throw a denser pattern than the other chokes, which is what you want when turkey hunting. The chokes that came with the gun I will use for everything else such as shooting clays, bird hunting, rabbit hunting, etc.
That's the beautiful thing about chokes. They really allow you to have multiple guns in one because they each have different constrictions. The term "choke" means just what it implies, it "chokes" or constricts the inner diameter of the barrel, which has different effects on your shot patterns. It's basically a hollow cylinder that screws into the muzzle end of the barrel. A cylinder choke has no constriction on your shot because it's designed to be the same diameter of your bore, which will lead to patterns that are a lot more scattered compared to something like a full choke, especially as you increase the distance between you and your target.
Chokes come in many different shapes and sizes and yes, they are designed to fit certain guns. For example, you can't screw a 20ga. choke into a 12 ga. shotgun. Also, some chokes are designed to fit a certain brand only, while others are designed to fit multiple guns. When buying a new choke, either the website or the box will tell you if it's designed to fit your gun. As far as chokes are concerned, there's really nothing to avoid that could note. Just make sure the choke you buy will fit your gun and make sure it's the right constriction that you need. The only thing I would mention is to make sure that the threads on the inside of the muzzle area and the threads on the choke are clean and lubricated because I've had my chokes almost stick inside my barrels before and it's tough to get them back out. As long as they are kept clean you will almost be able to remove them with just your fingers. Here is an article that I read a few months back and saved. Hope this helps!
http://shotgunsportsmagazine.com/archiv ... y0110.html