I grew up trapping muskrats, mink, and raccoon in PA. Don't have any experience with fox, or beaver (were no beaver then). I have fond memories of the scouting, planning, carefully setting my traps, checking my traps early in the morning before school and freezing my butt off. I used to skin muskrats in under a minute as I was my uncle's primary skinner and he caught many muskrats annually. If you are after animals that live near the streams, you can learn a lot while fishing looking for sign and other warm weather activities.
My suggestion is that you find an old timer and who has done some trapping and talk to him about it. (Perhaps at chuch? Post a sign.) If he is in good health, he'll go with you and show you some of the ropes. He can do this during warm weather actually and you can implement the ideas during trapping season. Check the Ohio DNR for seasons and so forth.
What animals do you want to trap? Fur Fish & Game is the best trapping magazine. There are books or booklets published that shows typical trapping strategies and layout. Check out HuntingPA.com forum on their trapping forum and it will be in the same kind of areas as you are trapping. It is fairly active. Good luck! You're enjoy both the challenge, the frustration, and the success of seeing your sets reap animals.
Hunting PA link:
http://www.huntingpa.com/ubbthreads/postlist.php/Cat/0/Board/UBB7
Like every other activity, you learn from your mistakes and you get better as you gain experience and confidence. About how old are you anyway? You'll need a skinning knife.... look at the Remington Trappers. These are pocket knives with long thin blades. You only use the top inch or so skinning for the most part.
If you are muskrat and mink trapping, look along streams in farming areas. In the summer you will see the trails from the creek to the corn or whatever. If there are muskrats, there are probably a few mink. Traps... conibears for muskrats (underwater sets primarily), and steel traps for other sets. Fox require larger traps. You'll need long rubber glove for setting conibears underwater when it is cold. Worth every penny! Landowner permission was never an issue when I did it as we knew everyone. But, I would ask permission from farmers. You will also learn if there are any other trappers planning on trapping their land that way. Lots to learn, but it is not that tough. Fox trapping is much more difficult as you have to pay careful attention to scents and scent control.