Theres a TON to them. this is one thread, there are 220,000 threads as of now. Theres infinitely many options as far as what pv setup youll settle down with. but for now just pick a kit that meets you current specifications, and when your specifications change, get another pv!
You will learn things like resistances, your "happy spot" with voltage, OHM's, and mods before you know it. Dont get overwhelmed, get something simple, then spend days on end obsessing about on ecf learning cool stuff :]
And be sure to pick up a lot of different GOOD flavors, the juice is as important as the piece!
If you were a pack a day smoker, get a high nicotine level (24mg) and various flavors from a reputable source. You have to trial and error a lot to find your sweet spots.