I use to ride hard, race a little.. was pretty serious into Cycling. Also a musician. In may of 95' my son was born and I had to pick music or cycling as my obsesive hobby.. not enough time for both. I picked music, went from 165lbs to 195lbs and no excersize.
June of 2004 (9 years later) I did this provida.com diet and lost 20lbs in 2 months. August I took my bike for a spin and like the other poster quickly remembered why I liked cycling so much!
October 1, 2004 my wife quit her job, for good, which free'd up a lot of time. Now I have the time to train again. We talked it over and she agreed to give me 10hrs a week of ride time.
Mid november was a local MTB race, first of a 4 race series. Last race was mid december and I finished 3rd overall and first in my age group. Granted, part of my placing was a result of attending all the races, but I wooped up on some guys.. plenty of young ones too! (I'm 41).
Anyway, I was amazed at how quickly I snapped back. After a couple months I had a sizable amount of conditioning. I didn't lose it all, thats for sure. But i do contribute much of the rebound to loosing weight and starting cycling without a lot of baggage.
So there ya go.. I have been off the bike for 9yrs, and after a few months of cycling I am really pumped with how quickly it all (well alot) came back.
as far as tips.. I just started riding. Small gears, hi cadence and just recently have been pushing the bigger gears. I train under LT right now, zing it on hills occaissionally, but definitely base training. Oh, and real long warmups.. I like a good 20-30 minutes of spinning. Things just take a while to get warmed up.. but they do!