California Academic Press - This site deals primarily with the assessment of critical thinking. www.calpress.com
Core Concepts in Critical Thinking - Heavy, but required, reading for anyone serious about the effective teaching of problem solving skills. www.kcmetro.cc.mo.us/longview/ctac/corenotes.htm
The Critical Thinking Community - Contains guidelines and lessons for integrating critical thinking into existing curriculum. www.criticalthinking.org
The Math Forum: Teachers' Place - Teachers' Place at the Math Forum provides Internet resources for lessons, projects, and software to help in the math classroom. These pages also provide many resources for communication with other teachers and links to professional organizations. mathforum.org/teachers
The Math Projects Journal - Site offers tips and lesson plans for interactive projects. Also includes advice from education professionals around the globe. www.mathprojects.com