Over 200 very well-written “How to” articles on bicycle riding, maintenance, and upgrading written by a highly-regarded and beloved bicycle guru, the late Sheldon Brown. Even if you don’t want to maintain your own bike, you should read the articles that interest you.
A very active on-line cycling community of forums for virtually every type of bike, type of riding, or type of rider. Also includes regional forums and a market place to buy and sell. For “older” riders, be sure to check out the Fifty Plus (50+) forum.