1) You can never go wrong with jeans. BUT don't get those skin tight emo jeans OR the thug baggy jeans that hang halfway down your ass, NO high-waters, you gotta get tthem to be baggy but not extremely baggy, a little loose but not too loose. Kinda hard to explain.
2)Get a mix of athletic wear and preppy wear, track jackets, polos (dont get the really tight polos it will just make you look like a douche), nice button up shirts on occasion (button only the bottom two or three buttons). T-shirts (Same as polos, don't get the tight ones. I recommend Fox Racing shirts)
3)As for shoes, that's a tough one. Get a mix of skater shoes(DC's) and regular sneakers (Adidas or nike)
4)Make sure colors match, girls will notice if your wearing a red shirt with blue DC's
5) If you need some more advice, take one of your female friends shopping with you, Females have great taste in fashion