Crush on a guy, don't know if he likes me!!!! HELP!!!!!?

i hav a guy in 4 of my cles. i've liked him for a while but im too shy to 'flirt'. im not even sure how to flirt with him!!! we're friends but not really good friends and im afraid too ruin what little relationship we hav! several times a cl i catch him looking at me(or the girl behind me). i'''ve asked him if he liked tht girl and he said no so im pretty sure its me he's looking at. there's one grl he's really good friends with though, but she only shows friend interest and im pretty sure she won't go any farther than just friends with him, you think he'll give up on her? plus he always talks too me, and when he needs things he always comes to me fr them, so do u think he likes me too??? and i also need flirting tips...badly!!!