You were checked to on the flop. With only one over and no bets, I am betting here to take the pot.

If I am called (or for some reason didnt bet the flop), and a card lower than 10 comes on the turn, and it is again checked to me, I am BETTING.

The same goes for the river. The Q on the river basically re-enforces the read that no-one has a Q, and a bet is a value bet and should be made. Personally I am betting more than 30, since if I am here I was betting previously. However in your case, since you checked behind everyone with what appears to be the best hand, a small bet (even a min bet like you did) would probably be the best play.