National Weather Service
The U.S. Government's premier website on weather. Weather news, safety, maps, etc. An awesome resource for severe weather information.
Weather Wiz Kids
An excellent site created by Meteorologist Crystal Wicker from Fox 8 Live Weather. Devoted to weather related education for children, teachers and parents.
Sirlinksalot.net: Lightning Links
A huge database of Lightning and severe weather related links. Dozens of lightning sites listed.