Ok, actually what you need to be doing right now is riding a bike (I hope). But if for some reason that's not happening/possible, then these YouTube channels are your next best bet:
Global Cycling Network - A one-stop shop for cycling fans. Includes trainer workouts, cycling ettiquette, basic maintenance, and explorations of bike culture.
Bicycling Magazine - Simple fixes, as well as gear reviews and industry announcements.
BikeManforU - A true character who discusses all the aspects of riding, gear, and repairs. Not for the spandex and carbon crowd, not for fans of competitive racing, just a small town bike shop owner with decades of experience he's willing to share in his own, uh, unique style.
MBRMagazine - Solid gear recommendations, fix-it tips, and MTB test videos. Oriented (obviously) for trail riders, not roadies.
Red Bull - I do not like Red Bull, as far as something I'd want to put into my esophagus goes, but I have to give it to them for sponsoring, promoting, and creating some incredible action/extreme sports videos. I wish they'd just drop the beverage part of their business and stick to the extreme sports. Oh well ... anyway, their mountain biking playlist is just an awful lot of fun to watch:
What are your favorite YouTube channels for cycling videos? Let me know in the comments.