if it's got choke tubes, you gotta use them. usually they come with i/c (improved/cylinder) which is least restrictive, modified-slightly more restrictive, and full- yet more restrictive. don't know what kind of hunting you do, but for upland game, shots around 30 yards or less go with the i/c. for ducks over decoys, 30-40 yds, go modified for geese or pass shooting ducks 40+ yards you might want a full. note that if you hunt waterfowl, make sure that the chokes are approved for steel shot (especially the full) they should be labeled as such. as far as slugs go, i think you can get a rifled slug choke. some are the extended variety and may be vented to act as a muzzle brake. also, there are a bunch of specialty chokes, like xfull for turkeys.
i just reread your post. cylinder is no restriction at all, then improved, then modified. use some anti seize choke lube on hte choke tubes once in a while before you screw'em in. as long as you have one installed, i think you'll be ok. you might want to take a big piece of cardboard out in the woods and experiment with different loads and see how they pattern at different yardage.

good luck with the new gun!


willy