In Outside magazine, and it has a nice/tough training guide. Its a 10.5 week guide for Ride The Rockies (2012 course), from Derick Williamson. Derick has a masters in sports science from U. Texas at Austin. He trains pro Ironmen, cycling champions, and marathon champions, and dedicated amatures ( no names given in the article).
I will show you what the first week is like if you wanna know.
Tues; 6 x 5 - min intervals (RBI 3 min) (Talk drops to short exclamations.)
Wed; 6 x 8 - min intervals (RBI 3 min) (Talk drops to short exclamations.)
Thurs; 30 minute ride (recovery/you could ride all day)OPTINAL
Fri; 4 x 5 - min intervals (RBI 3 min) (Talk drops to short exclamations.)
Sat; 60 miles with as much climbing as possible ( conversation pace)Enduarnce
Sun; 40 miles ( conversation pace)OPTINAL Endurance
In the first week 3 rides are optional. And that's pretty much the same for the rest of the training. I think its best to at least try to do the optional stuff.
On week 6 he starts to put in some intervals with the saturday ride.