A Star Wars question (20 characters later)?

after studying jedi dude's many answers to "7th movie questions" one must wonder, who was Darth Vader to be originally? and who was the other Skywalker? i'm very curious, coming from a guy that dosn't get bored of RPG's because he wants to explore more stuff and get more story of course i am. i am one of those people that look up on google vague things of star wars just to learn (that's how i learned about Revan before i ever played KotOR) i have looked this up but i cannot find the answer would anyone have any knowledge of this?