Mostly, as you go up in price, the lighter/stronger/more stable/spiffier they get. If you're riding cross country/trail riding, I wouldn't worry about the wheelset too much early on, unless you plan on hammering through rock gardens at high speed or doing drops. Just keep an eye on them, and keep the spoke tension up. If the spokes start making noise, get them serviced. It's easy to find strong cheap wheels, but they are usually heavy. You may not care at your weight.NewDIrt said:
The thing is, if you got a Jeckyl with a Lefty fork, you're in for a super specific front wheel. You have to get it built up with the C'Dale special hub.
You can get wheelsets that are better for clydesdales, beefier spokes and more of them, like a 36 spoke wheel as opposed to a regular 32 spoke. You can also go with beefier rims, like RhynoLites. These options add weight, but they will last longer.
Also, machine built wheels tend to be cheaper than hand built, but a well made hand built wheel generally lasts longer.
Right on about taking up the sport. Keep it up!