trent's right. Most of them go all-in with or withought a hand, it's dangerous sometimes to call. Thats why you have to use ur best judgement when it comes to this. Any two face cards, meaning, 10, J, Q, K, A or pocket pairs over 7 u should call, anything else pitch it. If u get beat, it will probably be beacuse of luck. Again use your best judgement when it comes to it.
Later in the game you want to be aggresive, otherwise, when it comes later and later in the game, everyone would have already have doubled if not trippled your chip stack. Take advantage early in the game when all the morons are playing.
Good luck!