Ditto what Rob said. It's all about the doe. Her estrus cycle runs approximately every 28 days once she starts. Some may start as early as september and go as late as Feb depending on wheather or not she gets bred.
Pre-rut is basically when the bucks are getting ready or may be chasing a few does but the does may not be ready. Several things can trigger or delay the rut such as moon phase, weather etc.
The peak of the rut is when the does are "in" and are able to be bred. This is when you see bucks acting like fools.
However, not all does are on the exact same cycle (similar to human females) so it's difficult to say exactly when a given doe in a given area will be "in".
For this reason, it's imortant to remember that "hunting the rut" may be missing the point. I know guys that say they only hunt the rut but these are generally guys that live in the suburbs or city and dont spend a lot of time in the woods. Good luck.