Since you can't really train for a 10 hour ride in your basement, I created a "program" for myself. 3 days a week, I use the elliptical (which groans under my weight) for 20-30 minutes then I do some strength training. 2 more days per week I ride the stationary bike for as long as I can stand it. I use an interval timer to tick off the time and every two minutes I change the resistance (going up and down the bike's resistance lever) to simulate hill climbs. After 30 minutes, I let myself downshift one gear. Currently I'm doing about 14 miles over 50 minutes.
Last year, I moved my bike riding log over to Facebook so that other people could use it - it now has ~250 users and occasional bug reports and enhancement requests. A jogger asked me if I would write a version that does running - I decided I would, but that I would extend the idea to cover other kinds of distance exercises as well - so I'll be able to post my stationary & elliptical progress as well.