When I was your age (EEEEeeekkkk!! Can't believe I typed those words ... I'm ONLY 29
) I really wanted to start taking care of my skin as well, and saw a dermatologist for the first time.
She put me on a skin care regimen that consisted of a glycolic acid facial cream in the morning and a retin-A combo at night. It has worked wonderfuly - both products actually stimulate skin cell turnover and cause the outer layers to slough off - almost like a mini peel every day. I do have to deal with some occasional flaking, but these products have definitely kept the fine lines at bay.
As far as non-prescription stuff goes, I love Neutrogena's tinted daily 30 SPF moisturizer - it gives your skin a subtle glow and protects against sun damage - I can go without foundation when I wear this.
Stuff from Sephora ...hmmm ... not sure if you have oily skin or are into Bare Escentuals, but the mineral veil is nonestly a miracle product- it's a finishing powder that goes on almost invisibly, gives you an "airbrushed" look, and keeps my oilies at bay all day - which is a miracle because I have super oily skin and with any other powders I get breakthrough shine within an hour of application.
If you're really bored and want to browse product reviews, definitely check out
Makeupalley - Street Smart Beauty - Homepage ... i always look stuff up there before I buy - it's a great resource.