Here's a tip that should help most people in this forum, one of the biggest mistakes I see (especially in live tournaments when blinds are rediculous).

(note: M= the number of orbits it will take at the current blind level before youve antied/blinded out)

If your M= 6 or less, NEVER NEVER NEVER raise preflop, then fold!!! In fact you should just be shoving most decent hands and only raising the premiums to induce more action.