Don't get drunk while you're playing!
Yes, for certain follow this rule.
Also, it depends on what you are going to play. Limit? No Limit? 3/6, 4/8?
In the lowere limit games, remember that it is more of a science. Know your pot odds and implied odd as they are relatively easy to figure out in limit. Alspo, be prepared to throw away many many hands. Don't get impatient. At the lower limit tables, you'll run into a lot of people who have learned everything they know about hold 'em by watching the WPT.
Be observant, and make note of it when someone overplays their strong starter post flop. For instance, if you see a guy move at the pot post flop with an AK that has completely missed, know that this guy is probably a home-game fish who will try to protect his hands too late. Its something that I've noticed time after time since the TV boom came about. In the 7 or 8 years prior to the TV boom, I rarely noticed it, but since, I see it at every table I play at, and its a great indicator of the caliber of player you're up against.
About 70% of the time I would say to let your opponents bet at the pot if you're on a draw rather than taking the lead yourself. You of course don't want to be 100% consistent, but if you let them bet at it, by the time the turn rolls around, the pot odds are usually more than sufficient to justify calling a 7 or 8 outer on the turn as you'll only need to hit about 1 in 9 or 10 of them to show a profit. This all of course applies to limit poker.
Also, always always use your position to your advantage. I can't stress enough how important position is in both limit and no-limit. Pretty hands Like KJ or KQ in early position are not the kinds of hands to fall in love with, and they become more playable as the button moves closer to you. Sometimes the hardest thing to do at the table is muck these pretty hands in first or second position, and then see what would have been a favorable flop, but in the long haul, you're better off getting away from them in early position because you could then be forced into a two-bet or three-bet situation with all the potential action behind you.
Remember also that most hands are going to end up being heads up by the time the river comes around, and that usually means that out of the 9 players that are in the hand, the two hands that have connected with the flop best are usually the ones at the showdown, not necessarily the best starters. Be prepared to fold a lot.
Change gears as well, Spend most of your time in first gear, but when you hit a rush, jam it up to 5th and maximize. It will create fear in your opponents as well as confusion and will cause a lot of forced errors. When the cards are coming. Use them to your best advantage.
Now, if you're going to play no limit, you have to be more careful about the implied odds, as they can seem to justify certain calls and bets, but you have to take into account that you can be wiped out by the turn of one card. Bluffing is a far more powerful tool in no limit than in limit, but also you need a far strong hands to be calling down large bets than in limit. Position is even more important in no limit as well because the action behind you can really get smokin.
Also, make sure you're not playing with the rent money as you'll be too cautious and will be more likely to lose. Use a bankroll that you can afford. Ironically, if you're almost willing to lose the money, it will make you more likely to win. But playing scared is almost always a losing proposition.
But if I were to put it all in a nutshell, I would say be patient, bluff rarely, play your rushes, remember position, use pot odds and don't drink.
Have a good time. Let me know how it goes.