TALK to a dermatologist. They can REALLY help.
Some suggestions I would have are up to the individual's health, and most are prescription, but it helps when people are honest. This has what worked for my friend... he had sever acne in his teens and in his mid 20's corrected it.
* Retin-A helps your skin speed up it's renewing cycle. It can help push the scarred tissue out and grow fresh tissue.
Depending on your age (if you're in your teens I'm not sure how much of the following is acceptable, best to ask), you can also get
* Microdermabrasion series. At about $125 a pop, you'll need six over the course of 6 mo - year. They will gently use a sand and suction to exfoliate your face and bring down ridges.
* Dermabrasion/laser. A much more agressive procedure, but will resurface your facial skin with sanding similiar to micro.
* Chemical Peel. This will use chemicals to resurface your facial skin. This is usually successful at acne scars and fine wrinkles, but it is very agressive and a last thing to try, not the first.
Good luck with whatever you do! I really do recommend a dermatologist though, they are there to help!