I got started this year, so I'll throw in my 2 cents....
Read all you can that is applicable to your area. If I read another &^%$ thing about dirt hole sets, I'm going to lose my mind. There is no dirt visible here from before the start to after the end of the trapping season.
Knowledge is always good, but you have a limited budget of time, so use it wisely. FFG is entertaining, but you might have a better connect percentage on trapperman archives (their "basic sets" links are worth a look), youtube videos, etc. I have better retention for things I've seen than things I've read about in general.
Talk to locals. They know what works and lots of them are willing to share info, experience, and sometimes even traps. Joining the local trapping org is probably a good way to do that.
Get out. Look at places you are thinking about trapping - just like scouting for hunting season. Look at tracks, sign, and think where you'd set traps if you could. If you can set traps, do it.
Stay as local as you can in order to shorten the feedback loop. The more often you check traps the more you'll learn what works and doesn't, the more you'll be able to reset, the faster you can adapt. I wouldn't be afraid to range wide in order to target what I wanted, but having something close by would be awesome.
Trapping is a lot of fun, and very addictive. I'm never going to make any money at it, but I don't make any money on hunting or fishing either.