I've been trapping professionally for 30 plus years here in northern Canada. Beaver are not that hard to catch and a good species to start with. I use entrance sets for them 90% of the time. Check your regs though as that might not be legal in your state. Fur Fish Game is a good resource. I write for them often, as do some other really good professional trappers. Trapperman is also a good resource once you learn how to cut through some of the BS.

You can do very well financially if you learn the markets. A friend of mine from WI trapped out west for a month last winter and made enough money to build a 30x40 shop. He concentrated on bobcats mostly. I was at a small fur sale yesterday and watched trappers selling tanned fur like hotcakes. Lynx were going for 750-850 and wolves were even higher. Tanned beaver will sell for 150-200 depending on size all day long. Lots of ranchers will pay you to trap coyotes. I know a few guys that do really well trapping problem coyotes each year. Same with farmers and beaver.......bottom line is the market is alive and well if you do your homework. Good luck!