This tutorial on knife-sharpening in amazingly comprehensive:
Knife sharpening is not difficult. It is not shrouded in mystery. With a little knowledge, a little geometry, a couple of tricks and some inexpensive tools, knife sharpening can be fairly easy and extremely rewarding. At the very least it’s a great skill for the toolbox. You’ll come away from this clinic with a better understanding of edges, steel and how to maintain your knives yourself. Or, if you decide to send them out, you’ll know how to make sure you’re getting what you want – and what you pay for.Link (via Megnut)
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.