What does it mean by "they see me rollin', they hatin'"?
Solution 1:
Rolling
could mean driving/cruising around specifically or it could also be taken in a much more general sense to mean "conducting myself (publicly)".
Google around for the expression "that's how I roll". Also see the music video by Chamillionaire "Riding Dirty" - or much better yet, its parody by Weird Al Yankovic: "White and Nerdy".
Solution 2:
It refers to Chamillionaire's song "Ridin". In it the rapper criticizes police for discriminating certain groups of people (afroamericans and latins).
In short, the police sees a black person "ridin" his car, hates him for having his financial condition, supposes a black person only would have such money through crime, then stops him, only to be frustrated by the fact that he is a hard working american citizen.
Nowadays it is commonly used in the internet to refer to "haters", people who blindly criticize certain people or points of view out of pure dogmatism.
Solution 3:
Well, at school, people do say it. My little 3rd grade brother says it; I sometimes say it with him. But anyways, I think it means that people are hating because they see you rolling in a car: they see you looking nice and they just can't stop HATIN'. "They see me Rollin', they HATIN'; trying to get me riding dirty" — that's more like they HATIN' because they see me rollin' in a car, they see me riding dirty. That's what it means to me, at least.
Solution 4:
"They see me rollin they hatin" refers to the police that are showing hate to black people ridin all nice and dope in their perfect cars.