As someone who has commuted by bike for more than 20 (closing in on 30) years, I have picked up knowledge and information from the street. But Commute by Bike is a fantastically informative website for commuting riders who don't want to wait for trial and error.
One thing struck me right away. When I left racing behind I took that intensity into transportation. I felt my money and energy were better spent in something that helped me physically and economically, as well as helping the environment and urban congestion, for all that congested urbanites did not seem to appreciate it. That reasoning and that spirit are strong at Commute by Bike. One commenter said that he got as excited over lighting systems and other practical componentry as he had over go-fast racing equipment. It's true.
Go check out Commute by Bike. Just don't forget to swing by here, too.