One of the best books on the subject is (in my opinion)
The Ultimate Ride : Get Fit, Get Fast and Start Winning with the World's Top Cycling Coach by Chris Carmichael. You can find used copies at very reasonable prices through
http://www.abebooks.com/
Chris advocates and coaches a system of training called Periodization, essentially breaking up the training year into four major subgroups, peaking in terms of fitness and preparation for the racing season. A great read.
Dave