exfoliate daily with either alpha-hydroxy cream, or a facial scrub. I have been using a cream called Pentaxyl which is supposed to treat fine lines and wrinkles. But I am skeptical of anything that is not FDA-approved. Too many snake oil salesmen.
I heard of some prescription cream called Renova or Retin-A. What is the difference between these two? Is there anything else that i should know about how to take care of my skin?

You should not exfoliate everyday, but only once a week, you are exposing your skin to too much abrasion and it can make it more dry. And you should not use a mechanical exfoliant (scrub) and a chemical one (like your cream) together, use one or the other. Your daily skin care regimen should include: cleanse, tone, moisturize & protect in the daytime (sunscreen) and at night use a nighttime cream that can help with wrinkles, etc. Retin-A and Renova are somewhat different, but not that much, you would have to ask a dermatologist if you even need to use it.