Vitamin E oil is helpful. Also, take it really easy when you have sex again - find positions that will reduce the amount of pressure on your tear site.
If you have had an episiotomy, know that your scar will be deeper than a tear - a cut will go into muscle, and there will be more soreness and bruising.
Use lots of lube and take it easy. Go slowly and gently, stopping anytime you feel pain. Make sure your partner knows that YOU will be controlling the penetration, etc.
Above all, be easy on yourself. Especially if you've had an episiotomy, it does take more time than we would like.