Dang, you guys are making me want to get back out there. My real job and 2 years of summer/fall drought have kind of taken the fight out of me. Muskrat were my bread and butter and all the small water has dried up the last 2 years. High prices brought all the fools out of the woodwork on the bigger water with public accesses and I lost most of my dryground land to housing developments and ownership change (people who think trapping is evil) so I hung up my steel for awhile.
For someone just starting trapping, I'd recommend targeting muskrats first. They're easy to trap, easy to drown, easy to skin and stretch, and quite profitable lately. If you're setting where coon are a possibility, upsize your traps a bit and stake securely or use a brushy log for a drag. I'm REALLY partial to the sleepy creek 1 1/2 longspring for water/streamside sets. They're a very well built trap. Heavy for drowning rats, strong enough to hold a big boar coon and almost indestructible. More expensive than other options but worth every penny. A close second would be the Duke #11 "double" longspring. Same qualities as above but will require some fine tuning. If coon are unlikely, sleepy creek #1 longspring,or Bridger #1 coilspring with a 3 ounce sinker wired to the chain 4 links above the swivel will work very well. You'll also want some #110 body grips for setting in underwater runs.
For land sets on Coon or Fox, I like the bridger # 1 1/2 coil. I also had some mixed luck with #160 bodygrips on coon when I trapped a property that had free-range dogs. I set them in boxes with the traps set too deeply for a dog to get into it. My favorite coon bait was chicken guts I got from a local butcher laced with a drop of anise or clove oil. If there are coyotes about, I will run a #2 Bridger double jaw. Good stout trap that will hold yote's. Trapping canines or cats is a whole different ballgame so you'd do best to gain some water experience first. The MN trappers book listed above is a very good reference. Check out Minnesota trapline products for more helpful literature, complete supplies and more literature. If nothing else, now you've got something to shop for at flea markets, auctions and farm sales.
