Discovery Education
http://school.discoveryeducation.com
Science problems solvers and general education resources.

BBC Education
http://bbc.co.uk/education

Programme for International Student Assessment
http://www.pisa.gc.ca/math_e.shtml

Attributes of High Achieving
http://www.pasd.wednet.edu/school/fr/diann/students.html

Boston University Physics Department
http://physics.bu.edu

School Science
http://www.schoolscience.co.uk