This page is full of online resources for teachers. If you would like to see online sites designed for student use, click here and choose a subject area.
http://proteacher.net/ - A collection of message boards where you can ask questions and glean wisdom from other teachers
http://www.primaryresources.co.uk/ - Documents and ideas for many subjects
http://pppst.com/ - A collection of PowerPoints great for the classroom
http://www.lauracandler.com/ - Great resources, including cooperative learning resources
http://www.watchknow.org/ - A collection of free videos for learning
http://www.educationworld.com/ - Excellent resources and articles
http://www.edzone.net/~mwestern/stuff.html - Technology tips for teachers; lots of links!
http://www.wholebrainteaching.com/ - Lots of resources for keeping your class actively involved - These are the rules I use in my own classroom.
http://www.smartclassroommanagement.com/ - Regularly updated, this site has very helpful articles
http://teachers.net/wong - Articles written by Harry and Rosemary Wong
http://thecornerstoneforteachers.com/ - Many resources - Angela's World's Easiest Token System really is easy!
http://www.newmanagement.com/ - Rick Morris' site with lots of classroom tips
http://www.readinglady.com/mosaic/tools/tools.htm - Great resources! Subscribing to this listserv will give you great ideas for teaching reading strategies.
http://www.readinglady.com/ - A great resource
http://www.writingfix.com/ - Resources for Six Traits lessons
http://www.readwritethink.org/ - Resources from IRA and NCTE
http://www.dr-mikes-math-games-for-kids.com/ - Tons of printable games; as well as online games
http://www.aea7.k12.ia.us/cia/math/Routines.html - Daily math reviews and mental math questions for grades 1-8
http://www.math-drills.com/ - Many free math worksheets
http://illuminations.nctm.org/ - Resources from the National Council of Teachers of Mathematics
http://www.educationworld.com/a_lesson/archives/boxcars.shtml - Math games using dice and cards
http://www.ncpublicschools.org/curriculum/mathematics/elementary/ - Math resources from North Carolina, but great for teachers in any location
http://www.nsa.gov/academia/early_opportunities/math_edu_partnership/collected_learning/index.shtml - Hands-on math units developed by teachers at National Security Agency summer institutes
http://www.sciencenetlinks.com/ - A wide variety of science resources
http://www.learner.org/jnorth/ - Track migration and seasonal changes with your class; provides opportunities to collect data collaboratively with classes around the world
http://www.mrdonn.org/ - An excellent resource on a variety of topics; I've used these pages as an alternative to my textbook for some topics.
http://www.cyberbee.com/wwho/ - A simulated wagon train journey facilitated online