In six handed limit Texas Hold em then there are three main factors that you need to consider when you think about betting the flop. These are your hand strength, the flop texture and also how many opponents you have. Let us look at a few examples here to highlight what I mean. You have raised with A-Q from the button and both blinds call you. The flop comes 9c-8c-7d and both of your opponents check. With two opponents and a connected board like that and I would certainly not bet this flop! I would check the flop and look to take the free card.
A flop like that has hit the range of hands that call raises. Any ten or inside straight draw will call you and your equity is quite low in this situation. Let us look at another example and you raise from the cut-off with K-9s and only the big blind calls you. The flop comes Ad-8c-4s and the big blind checks. Here a bet is fairly automatic as you raised pre-flop and so you can represent the ace that arrived on the flop. Also if your opponent calls you on the flop then you can check the turn and take the free card and get to see the river for only one small bet.
The combination of only one opponent and the board texture means that a bet is automatic here. Now let us look at a rather more complex example. Here you raise from the cut-off seat with the Jc-10c and the button and both blinds call you making a four way pot. The flop comes Q-Q-10 and now both blinds check to you. Here you are still correct to bet although if you get check raised then you have somewhat of a problem. If your opponent has a draw then they have at least eight outs against you. If they have a ten with a bigger kicker then you are also in trouble.
If they have a queen then your equity is even less. Despite the fact that you have three opponents and a vulnerable hand then it is still correct to bet this flop. Let us look at another example and you raise from the button with As-2s and both blinds call you. The flop comes K-7-3 rainbow and both opponents check. Here the board is dry but you do have two opponents. This is marginal but I would lean towards betting instead of checking. This is where you are betting through the small blind. When you bet then they have to worry about the big blind after them who could raise.
So if the small blind folds and the big blind also has nothing then they could fold. But here is where you can make a better hand fold because let us say that the big blind has a hand like A-4 and they see you bet. This is going to look difficult for them and they know that if you have paired with a king or a seven or a higher pocket pair then they could be drawing to only three outs to their ace as pairing their four may be no good.