scholastic.com/bookwizard

Great online database which has countless books and reading materials ranging across all reading levels available.

earth.google.com

A fantastic geography resource, this website provides an interactive map and shows images of any location on Earth.
facebook.com/scholasticteachers

Updated weekly, the site offers worksheets, lesson plan ideas, and other helpful information.
teachertube.com

This website is loaded with helpful clips that are useful for complementing the lesson that they are teaching.
nlvm.usc edu

Mathematics centered website that offers math games for kids in any grade.
nsta.org

An excellent resource for teachers who are new to teaching science, this site features plenty of ideas for lesson plans an in-class experiments.
tolerance.org

A blog featuring posts for other teachers that offers suggestions for teachers who are being to teach about "tough topics", such as The Civil Rights movement.