what you should be looking for as soon as you sit down

There's a lot of information you can get about the game you're playing in right away, before you sit through several rounds of the button and watch a lot of hands play out. This information can give you an edge right away to help you make correct decisions against your opponents, and increase your potential opportunity for profit.

First, as Mike Caro would say, look for the general demeanor of the game. If it looks like the players are laughing and having a good time, that's way better than if the table is playing quiet lockdown poker - people are gambling. Also, take notice of where the chips are - who has what amounts, where they are seated, etc. Pay special attention to the way in which players have their chips stacked, and if any chip stacks are exceptionally neat or messy, that probably indicates tight and loose play, respectively (of course this doesn't apply to messy stacks of players who have just won a big pot and haven't had a chance to add it to their stack yet).

One thing though, that you always want to notice in the first few hands is the rate of calling versus raising preflop, and how many players are entering each pot and staying in for the flop. If there's a lot of calling by a lot of players, and not very much raising, you are in good territory. You are most likely facing a lot of calling stations.

In Doyle Brunson's Super/System, he has the following to say about playing against this type of player:

"The perfect opponent to face is the Calling Station. He's similar to a loose-drunk player, but he rarely bets. Most of the time, he just checks and calls. And if you can't beat a man who always checks to you. . .you can't beat anyone.

Timid players don't win in high-stakes poker."

You have to notice your opponent's tendencies. This is a must because it's correct to play each opponent differently, and in general you want to tighten up at loose tables and loosen up at tighter ones. There are concrete reasons.

Consider this: What, by definition, does an exceptionally tight player do wrong? He/She calls too much. Similarly, a too-loose player calls too much. If your opponents are making habitual mistakes, encourage it. The tight player folds all the time, so you may as well agress against the tight player. Let him/her keep folding. They'll be doing it when they have you beat. Let the loose player pay you off. And if you're up against a player who bets and raises all the time, you'll have to call more, because on average he/she has a weaker hand. Also, against this type of player, it is enormous to have a monster hand, since in many cases they will do the betting for you, and if you have the nuts you can stick in a huge raise on the river, hopefully after they've pot-committed themselves by betting all the way down.

Sometimes, if your loose-aggressive opponent is in position against you, you are presented with more opportunities for check-raise rebluffs. This is a risky move, as it essentially risks two bets rather than one. However, with knowledge of your opponents and careful timing, it can be done. In order to try, however, I'd have to be extremely sure my opponent was capable of folding.

Of course, you can still be check-raising with the good hands that warrant it as well. In fact, I suppose more hands require a check-raise when facing a super-aggressive player out of position vs. a normal one, since they'll bet when checked to much more often.

However, you still would much prefer to have the loose players to your right so that you can avoid being out of position against them. Particularly if they have a lot of chips.