When you are in an early position, you must clamp down and only play premium hands.  It is most difficult to exercise patience when you are in this position.  You only want to play hands that can stand a reraise from somebody to act after you. You do not want to gamble with speculative hands.

Typically from early position, you will raise with a pocket pair of Queens or higher, AK, and sometimes AQs (although you will not be losing much by folding AQ from an early position).

Pocket jacks and tens can be played from an early position (but be prepared to dump them if there are two more raises behind you). Whether you raise or just call the big blind (also called "limping") with TT and JJ is up to you, but you should mix it up. You never want to play a hand the same way every time. More observant opponents will pick up on your betting patterns and be able to more accurately predict what you have.

You can also limp in with big suited cards like KQs. Beware of hands like AJ, AT, KJ, and QT (and even KQo) from an early position. If you raise with these hands, you will eliminate all hands except for ones that beat you. Additionally, you will be playing out of position the rest of the hand with a weak hand. Throw away these hands from early position. If there is a raise from an early position player before you, only play the strongest hands (AA, KK, QQ, AKs). Throw away the rest! Remember, if somebody before you raises in an early position, they probably have one of these strong hands. It takes a much stronger hand to call a raise than it does to raise yourself. Do not get caught in a losing battle!