Kodak's Taking Great Pictures. The entry to a host of tutorials and information about photography. A series of courses on a variety of introductory and specialized topics. Free but requires registration. Chapters from an evolving text by Phillip Greenspun.
Site has many good links as well.
Fodor's Focus on Photography. A guide to photography by the Travel people. Photography at SunSpot. A nice site from the Film people An Introduction to Photography by David Barnes. Mostly text but a nice concise intro to basics.