-Don't burn bridges if you work for a powerful or highly respected company. These people know people, and if you can't use them as a reference, it looks bad. If you can use them as a reference, you have so much going for you.
-Watch your mouth until you get a feel for the office and even then, be careful. Not only should you not swear, but also don't gossip. It can be destructive and create enemies.
-Show up on time and show up and actually work. It's a given, but you wouldn't believe how many friends of mine are late (not like 5 min, significant) and don't understand why their bosses are pissed and reprimand them. Actually doing work means don't screw off on the Internet; a friend got really yelled at for that one.
-Be aware there are simply some things that occur in most offices. Gossiping, unfriendly co-workers, boss not there to hold your hand and go "Atta girl" through project. People suck, and you have to learn to cope with that, as well as working independently. It isn't perfect, but you have to weigh your complaints out. Again, I've had friends who've quit jobs at the slightest problem, when the reality is that it wasn't that bad and it's the kind of thing that happens a lot of places. Nothing in life is perfect With that said
-Don't put up with extreme BS. Sexual harrassment, company bad ethics, Wal-Mart style abuse of power, extreme stupidity from boss (one of my friends was written up for taking off to take care of her miscarriage) those are valid reasons to quit.
Finally, the only other thing I can say is if you're not in love with your job (you're just okay with it), keep it and look for another job or learn to deal with it. Your first job isn't supposed to be your dream job and your career shouldn't be the only place you use for your identity