[Bob T.]

This is about education.

There wasn't a raise preflop. You don't know if or where there the action will come from on the flop.

Your hand is definately going to see the turn, in fact, you will probably be seeing the river regardless of the turn card or action.

It is checked to you.

Given all of those conditions, a bet is mandatory here.

Only good things can happen.

1) you might win the hand right now.
2) you could at least fold the players left behind you, and you might win the button for the rest of the hand.
3) you might eliminate all the players other than the flush and straight draws, which would make you the leader going to the turn, and gives you the best chance to win unimproved.
4) Another queen might come on the turn, and now you could convince everyone to fold.
5) You might have the option to take a free card on the turn.
6) everyone could call, and now you are getting 4-1 when you are only a 2-1 underdog.
7) It provides a little doubt in your opponents minds when you do flop top pair/two pair/set and bet, because they know you have bet draws in the past.
8) its limit poker, and the poker gods favor those who bet and raise over those who check and call.

There probably are some other reasons, but if these haven't convinced you, I'm sure the other ones won't help.