Ultra Race suggestions

I have been running for 20 years. The longest I have gone is 26 miles NOT in a race and my longest race is a 15k. The last few years I have decided I really want to step up my races though and really push my body to new limits. My current goals are to run a half marathon next April/May do a full in June or July and then aim for a 50 miler next Sept. I will have some other races mixed in ranging from 5-15k also.

I am willing to travel for my 50 miler. Any suggestions on the best races in the US or Canada? Does anyone have any website that are great for training schedules and what not. I normally create my own training schedule. However, I think I might need a little help with training for a race that is that long.

Any tips or suggestions would be great!