Assuming this isn't a short-stack tournament, I bet hard when I flop top pair early in the tourney. It forces people to play drawing hands out of their odds, it maximizes return on the hand if you hold up, and it clears all the noise off a loose, limpy, early-game table. I find this to be especially necessary in turbos, where you're playing anything you can while the blinds are low.
Early in the game, when everything's cheap, I expect people to hold on a street for a drawing hand or an overpair. Chances are, at this point, there could be 4 or 5 players in the hand in the early game. Betting full pot will most likely get you heads-up or 3-handed if not close the hand out entirely. Considering implied odds, 3-handed, the flush/straight draw may be into his odds, and heads-up they'll be out of their odds if they call. Then, on the turn if nothing hits, you can punish the board and close the hand out or (if you're feeling a little frisky and donkish (it's okay, we all get greedy)) v-bet to egg your opponent on. If something does come on the turn to scare you, or you think you just got smooth-called, you can check-fold without feeling like you've lost a whole lot. I tend to check the turn in the early game if someone calls aggression, mostly to feel the opponent out and see what he does when I give up my lead, plus I love to check-raise in the early game just to see if I can put someone on tilt.
Basically, early in the game bet hard on the flop if you hit top pair. You'll gain a lot of information about your opponent and the hand at play, and the turn will mean a lot more when it comes out, all for a good price.