I am 17 and into gun collecting. Welcome to the board. Most of the people here are really nice, and are full of many many lifetimes of experience that you can use. This board has helped me:
purchase rifles (duh! :D)
join the military (choose branch, help for BT)
get through those bad days where nothing goes right
I have been around for a year and am waiting for my first AR now. (being shipped) From someone who got the 10/22, go for the AR first, and buy a 10/22 later. The AR is an expensive rifle (cheapest is about $575 built), but a nice one. A 10/22 gets really tiring.
If you do get the 10/22, don't accessorize it, it isn't worth it. The hicap mags aren't worth the money, it's no fun with a scope, and the gun is fine how it is. If you get the 10/22, get the cheapest one you can find (pick up an issue of SG news, you can find the birch/blued ones for $119, ship to an FFL for $15 + transfer fee). Save up for an AR over time, buy it in increments. Lower, upper with barrel installed (saves gunsmithing), bolt and charging handle. Shop around and don't get brand names, unless you want a warranty (BM has 1 year, Armalite has lifetime, but both guns go for $800-950)
Good luck!
James