With medium pairs, it is far better to be the one going all in with that hand than to be the one calling an all in. If you have a hand like that, and the flop comes with an overcard, if you are in position and they check to you, put in a continuation bet, because noone has shown you any sign that you are beaten. If they call or raise, you can get away from your hand without committing any more chips, and if they fold, you win a pot. If you are out of position and made the raise and they called, then put out a continuation bet also, and play it the same, although since you are out of position, it's alot more dangerous for you since if they call on a draw and the turn doesn't help, its very hard to fire a second barrel into a pot like that, and a check is going to force you off the pot with the best hand when they bet your weak check.

For pairs like that, early, limp with them for set value, in middle position first in, raise with 99 or TT, and late position first in, raise with all of them. In a multiway pot, you want to hit a set with these hands. Heads up against 1 opponent, it's very important to have position so you know what your opponent is going to do before you decide on your move, which could be bet to take down a pot.