Well I suppose since you've never run, it might help you if I made you a little PROs and CONs list (this is just of Distance because 1. I'm too lazy to do a list for sprints, and 2. I've never been a sprinter) So...
DistancePros:
1. Keeps you in better shape overall than sprints
2. The distance kids are generally much closer, more "tight-knit" than the sprint kids, not to mention generally more focused overall on their performance and somewhat more "mature acting" (obviously there are many exceptions to that statement, it's just what I've seen on my team)
3. We have more fun

4. When you're conditioned and in-shape, race-pace of a 1600 or 3200 seems much more manageable than, say, running a 400 or 800
5. If you start out a slow runner, (provided you work hard) you can end the season relatively fast. You can't usually do that in sprints b/c with sprints, you basically have the speed...or you don't.
6. Distance kids are generally really cool people and even if you're not friends with them, they'll respect you if you work hard (and by end of season you will probably be friends if you weren't before)

Cons:
1. You'll need to train about 6 (possibly 7) days a week and run at least 20 miles per week for at least a month or so before you really start to see results (ie you'll need to start training around February or March)
2. Most of the distance kids run XC and will have trained year-round, so chances are they're gonna be faster than you and will run Varsity. (DON'T let this scare you away! You can improve!)
3. While many non-runners (spectators) and sprinters respect you for running 2 miles in a race, they also consider distance races to be some of the more boring parts of the meet (ie perfect time to get a snack, nap, then come out from hibernation to watch you finish your 8th lap). *Of course if you become a distance runner these races will become your favorite events of the meet, both to run in AND to watch.