I want to start learning about these two. Where would a good place to start be as far as the Knights of the Old Republic goes? I have started reading about them on Wookiepedia and am very intrigued but there is some much out there I don't know where to start.

The game is actually the best source. After that, Revan has his own book written by Drew Karpyshyn. There is an Old Republic comic, but its really only tangentially related. It is the first place Revan is called "the Revanchist". His "epilogue" so to speak is in the MMO The Old Republic. Hope that helps.