Hi,
I have done a 50 mile. The biggest thing that i noticed about an ultra distance is the slow pace. You have to go much slower than you would a marathon. The best local source for info would be Rod Hasker the president of PARC. There are a bunch of sites out there, here are a few that i'm aware of:
http://www.ultrunr.com/http://www.run100s.com/ Best of luck, the most important thing is think slow and steady, training is about more time on your feet, or otherwise moving forward.Anytrhing else just ask..PHIL