Stealing from Late Position
In poker you make a lot of money by betting at pots. One of the most common bluffs if the "late position steal". This happens when you are in late position and everyone has shown weakness, such as by checking around. A bet here is almost automatic. The thing is, even when people know you're on a steal raise, frequently they can't call. The two main times this happens are pre-flop when everyone folds around and you're on the button or one off the button, now you're just raising into the blinds who have random hands and will often have to fold. Even if they don't fold pre-flop, you can continue aggression on the flop and probably win then. The steal is also common on the flop when it checks around to you in last position. In this case you need to be a bit worried that someone is slow-playing or trying a check-raise. Obviously you can use their pre-flop action and the texture of the board to decide how likely it is they are trapping. eg. if it was raising up pre-flop and the board comes AQT, then someone probably has something, so the checks are very suspicious.
Now, what kind of hand do you want to steal-raise with? Well, if the table is very weak, you can do it with any hand at all. This is actually pretty rare; at a decent table, people will defend often enough that it's not +EV to steal if that's the only way you have to win. You also need some chance of winning with your hand when you're called. For example, against the blinds you need roughly a 1/3 overall chance of winning for a steal to be profitable. You might succeed in your steal 20% of the time, then you also need to be able to win 15% of the time when you're called. The "when you're called" is very important - you have to judge how your hand does against hands that are likely to call you. Because of that, hands like A2o and K2o are not good steal hands. The problem is that against hands that can call you, you're likely to be dominated, against eg. A6o or K7s. You actually prefer hands that are a little sneaker, like QTo, J9o, 65s, 33, and of course all better hands. These hands are unlikely to be dominated and play well against random hands. Hands like 65s are worth a special note; they work well only because you are going to represent high cards when they flop. That is, if the flop comes A98, you're going to bet as if you have the Ace. Often he won't have the ace and will fold it. Thus you win when the flop hits you (with a straight, flush, or even just a pair), and you win when the flop doesn't hit you (high cards), and when you add them up it can be very profitable. The same thing holds roughly for steals on the flop. You want to have a few outs (at least 4) to make a hand that can beat what he's likely to call with. If it checks around, you make a steal-bet, and someone re-raises you, you want to be able to call. At that point the pot is usually offering around 9:1, so you need roughly 5 outs to call. You get 5 outs with two overcards, any pair (not pocket), gutshot with an overcard, etc. If you just have a gutshot or just an overcard, you can usually call with just those 3 or 4 outs because your implied odds are pretty good - he thinks you're weak and will pay you off if you hit. Of course this is assuming he would check-raise with just top pair. If he check-raises too rarely, eg. only with monsters, then you just fold. Usually if good players see you doing a lot of steal-bets from late position, they will start check-raising more, and even start check-raising as a bluff or semi-bluff.
Now, how do you play against someone is stealing often? You see them frequently raising from the button and you suspect they often don't have a hand. One thing you can do is ocassionally try a check-raise bluff. If they are on a pure steal bluff, they will have to fold when you check-raise them. If it is pre-flop and they are trying to steal your blind, you are in a bad spot. The problem is they have position on you, and even if you think they have a junk hand, it's not that bad for them because position is a big advantage. So, from the blinds you should still lay down your bad hands to a stealer. With decent hands, like any ace, you call. Then if you make something on the flop, you play it a lot more confidently than you would against someone who plays more premium hands. The Stealer will probably give up to much pressure. The other big thing you want to do against the stealer is slow-play and try to make big pots when you get big hands. Be inclined to just check and call with your big hands as long as they keep betting into you. On the turn or river you can then check-raise and trap them for a big pot. Note that you should also be stealing a lot from the button, it's not a bad thing to be doing, and if someone is just stealing the correct amount, you won't really be able to exploit it; you can only take advanatage of a stealer if they are doing it too much or if they are very predictable about it.
As I mentioned above, stealing from the button against the blinds is almost always a good play. The small blind will fold very often because they're only barely in the pot; the big blind should then call with almost any hand, because they are getting 1:3.5 (22.2% pot percent) and no hand is that big of a dog pre-flop (assuming you steal with every hand) - even 32o wins 32% of the time heads up. If you make a steal with a bad hand and he does call you, you again can't possibly be that big of a dog. The correct play from the big blind against someone who is always stealing is to fold only your very worst hands (something like 96 and worse) and to raise with any good hand (all pairs, any ace, KTs or KJo or better), and call with all others. Note that the raise with any good hand here is very important, if you're just calling with good hands, the button is still taking a big advantage on you. The problem is that the dealer will be in late position for the whole hand, so if you are both playing junk, he has a much better EV. You can imagine if you both were just forced to play every hand for a raise, the dealer would be much better off. In fact, that's something you just have to give up. The player on the button is going to make more money on those hands on average (assuming you are both playing well). There's nothing you can do about that, it's simply an advantage to be on the button. Of course, you will make that back when it's your turn to be on the button, and when you're in the blinds you need to minimize his advantage.
Often I'll play in games where I can raise from the button in every single stealing situation (when it folds around to me), and the big blind will lay down hands like J5. That's a very marginal hand and very hard to play. Even worse for the big blind is if you call with a hand like J5 and then play it weakly post-flop. Say the flop comes 9TA; big blind checks, the dealer bets, and big blind folds - you're giving up a lot of money! When you're stealing from the button, if they just fold slightly too often, you make a lot of easy money in the long term.