Enchanted Learning – This is a subscription site, but they have a tremendous amount of free material. Topics include such items as: Little Explorers (a fantastic picture dictionary), Geography, K-3 Themes, Nursery Rhymes, Animal Printouts, Butterflies, Science Pages and Activities, Art and Artists, Inventors, Cloze Activities, and much more. This site is probably best suited for elementary classes. http://www.enchantedlearning.com/Home.html

Mary Scroggs Elementary School’s (NC) Interactive Math – This is a fantastic site put up by a K-5 elementary school in North Carolina. While their standards may be slightly different than ours (CA), I’m sure you’ll find many appropriate activities to motivate your students with. (I love their choice of mascot – they’re the “Scroggs Frogs.”) http://scroggs.chccs.k12.nc.us/tech@home/math.htm

Mathematics Lessons That Are Fun! – This is a VERY comprehensive site put up by Cynthia Lanius of Rice University. There are math lessons from Pre-K through 11th Grade. Everybody should be able to find something here that they can use. http://math.rice.edu/~lanius/Lessons/

National Center for Educational Statistics (U.S. Dept. of Ed.) Create a Graph – This looks like a very useful site from the U.S. Dept. of Education. In addition to teaching students how to graph and use graphing, the Students’ Classroom has Math Games and Activities and information about Surveys. (Try the Technology in Schools and Homes Quiz http://nces.ed.gov/nceskids/quizinet.asp.) This site looks appropriate for Intermediate Elementary and older.
http://nces.ed.gov/nceskids/Graphing/

National Library of Virtual Manipulatives for Interactive Mathematics – This is an awesome resource for teaching math! Despite their own academic-sounding description (following) this site looks easy to use and find uses for. Activities are set up using the NCTM Standards. “This is a three-year NSF supported project to develop a library of uniquely interactive, web-based virtual manipulatives or concept tutorials, mostly in the form of Java applets, for mathematics instruction (K-8 emphasis). The project includes dissemination and extensive internal and external evaluation. …Our Utah State University team is building Java-based mathematical tools and editors that allow us to create exciting new approaches to interactive mathematical instruction. The use of Java as a programming language provides platform independence and web-based accessibility. Ultimately we will make all materials available at several sources on the Internet, creating a national library from which teachers may freely draw to enrich their mathematics classrooms. The materials will also be of importance for the mathematical training of both in-service and pre-service elementary teachers.”
http://matti.usu.edu/nlvm/nav/vlibrary.html

TeachersFirst.com Reading Lists – Books for reluctant readers, by interest category http://www.teachersfirst.com/readlist.html

Yahooligans’ Animal Pages – Search their extensive library for mammals, fishes, insects, birds, amphibians, and reptiles. Images are shown with each description and fun facts. This looks great for all ages. http://yahooligans.yahoo.com/content/animals/