This is a pretty newbie-ish question, but here goes! My fiance and I are pretty new to the whole backpacking thing, but we've decided to take our first multi-day trip next month. Should be a 3 day, 2 night hike. We've done some day hikes and car camping, but never an extended backpacking trip, so I'm pretty new to certain aspects of it. We already have all the gear and everything, and should be in good shape as far as that goes.

My question is.. How exactly does one go about backcountry camping? I'll elaborate. I called the ranger to discuss the trail i'm looking at, and he said it's moderate difficulty, and has a couple of "primitive camping" spots that cost something like $8 a night, but he said that backcountry camping was free. If I understand that right, can I basically just set up my tent anywhere I want along the trail that would work well and is far enough from the path to not be an eyesore?

Being my first time out, i'd really rather not get on the wrong side of other hikers or a ranger by commiting some backpacker's faux pas. Any tips?