Like is a word often used as a filler (in the same way as 'um'), and it is also used when referring to someone's speech (e.g. "He was like "No way!"" means that the the person (he) said "No way").
It can also mean to fancy someone, to have a crush on them, to be attracted to them. The term "Like Like" is also used to mean love.
'Like' is also a Facebook term, meaning 'I'm a fan of this' or 'I agree'.