Congratulations on making such a commitment. You are bound to have a grand adventure learn a lot about yourself in the process.
My advice? Don't be in a rush.
If you have enough supplies, and you reach one of those epic spots along the trail, you know, there is nothing wrong with bagging it early and enjoying the view. Take a zero (mile) day by a mountain lake and partake in the splendor that few people will ever have the opportunity to experience. I guess I took that away from my thru-hike; the feeling that I rushed through places that deserved exploration and reverence, that would have been fantastic destinations in their own right.
A lot of people on here are interested in pushing the limits of distance and endurance. You will likely do both, but just don't forget that sometimes, the best hiking days aren't measured in miles alone.
Have fun and let us know how it turns out!