C is for Cookie Monster. There is a printable page to color for each letter, and accompanying collections of the same for numbers and shapes. Smokey Says Forest fire safety rules from Smokey the Bear, with nice graphics and games to reinforce the rules. The Children's Digital Library. The Public Library of Charlotte and Mecklenburg County in North Carolina has produced a fabulous collection of stories and activities, available in Spanish and English.
Many links organizes by theme.
The Kids on the Web List of links for and by children. Listado de sitios para y sobre chicos. Yahooligans Yahoo's children version.