You can learn a lot just by surfing. The American Society for Cell Biology (which I seem to be plugging a lot lately) has published a terrific set of lectures by some of the leading lights in the field. The full collection is at iBioSeminars, and they're all free. Most are at a level suitable for advanced undergrads, but (as with any field) some speakers are clear enough that even someone with almost no background could follow easily. Martin Raff is one of my favorite communicators: here he is talking about how an organ -- or organism -- knows how big to grow: Quicktime moved below the fold so it doesn't keep loading with the home page...
(There are two more parts in his lecture.)
I also highly recommend Cynthia Kenyon talking about aging -- and whether it can be slowed -- because she's an engaging and entertaining speaker.
Many of the others are wonderful, too. Browse around, learn something. It's incredible all the knowledge you can get for free.
I'll try to post one of these learning threads weekly, each Tuesday or Wednesday. Use the comments to discuss the lectures, or to pont me to your own favorite on-line learning sources.