langurmonkey: I'd love to play a pen & paper RPG with some people but I don't know how to start that. Which pen & paper RPG do I get into?
Doesn't really matter, I'd say. The most important thing is a good vibe between the players, if that's established pretty much every system will be fun. Unless you really like to try out something specific, say a certain setting or a rules heavy or light system, I'd recommend choosing your fellow players first, for example people of your age group, system second. Once you've gained a bit experience (I take it from your post that you haven't played before), you might wanna try out something different or have a better sense of which game exactly you're looking for, who knows.
D&D is surely the most popular system, but of course there's the big question of which edition to play. Pathfinder seems to be quite popular as well.
Best thing to do is probably joining a lively community, like the official D&D boards or EN world or whatever, google's your trusty friend here as it always is, and make a thread in the appropriate section. These guys know best how a newbie should tackle things.