I'd be careful what you get from Greek myths. In D&D centaurs are normally CG and based off of Chiron the teacher of heroes in Greek myths who raised Theseus, and Jason and was accidentally killed by Hercules. He was also the son of Chronos.

Other mythical centaurs were a usually Chaotic Evil race and are pretty much always the bad guys (which is not how they are in D&D at all). Actually the centaur divination teacher from Harry Potter is fairly close to D&D centaurs. If you want the official fluff, though, go to Races of the Wild or the 2e Monster Manual.