I'll hit on a couple of your questions. For training info, try:
UMCA
Click around a bit, especially under 'articles'; you'll see stuff about training for a century, or 24 hour race.
I think commuting can be valuable training time. You have to have training objectives and focus on them to make it useful, though. You might do a series of hard climbs, or intervals, etc., depending on you progress in your training plan, or you might use it as a 'recovery ride'.. If the traffc does not limit you from hitting your training objectives, then you can save some time and money by training on the commute.