Make Magazine is a fantastic geeky mag with an online presence from the O’reilly people.
They have just released a cool web2.0 mashup called Instructables. It combines a WIKI with Flickr for step-by-step collaboration of DIY projects.
People love to create. Creating is part of learning. Doing is a big part of learning. “Teaching others is like learning twice” (I don’t remember who said that.) So go ahead and create an instructable on something that you know. I’ll bet you’ll learn even more.