Last year I used the diablo schedule to train for my century, and the century ran very well. I'm disappointed it is no longer there, because i have another century coming up in June!

Here is what I am using this time - it is similar to the Diablo one:

http://www.maccfund.org/trek100/riders/train.pdf

Easy means, don't overdo it.
Pace means, at the pace you expect to do the century (so, if you want to do the century in 6 hours, for example, your pace would be +/- 16 mph... if you have a speedometer you can try to keep yourself in pace.
Brisk means above pace, heart is a-thumpin.

You can also change your rest days, move the schedule around a bit. I also cross-trained in there - did a day of running instead of cycling on an "easy" day, for example.

Best wishes,
Indi