MATH
http://www.homeschoolmath.net/worksheets/  Printable math worksheets for a multitude of topics that you can customize. 
Teaching Math with Money - A collection of links to a variety of sites for learning math through money. Lesson plans, activities, and video.  K-6th.
XtraMath - practice to memorize basic math facts
bigbrainz.com - Teaches times tables from 2 to 12. Free until you reach a certain level in the game. 
ixl.com - math worksheets by grade and skill (online practice, not printable)
coolmath-games.com
mathfactcafe.com
muliplication.com
coolmath4kids.com - Elementary math
coolmath.com - Pre-algebra
Master Math -  video lessons for grades 6, 7, 8, and Alg 1
FreeEd.net - covers a wide range, but best for more advanced topics.  Online text,not video
Georgia Virtual Learning - Also has other subjects, 6th, 7th and 8th.
mortgagecalculator.net -  The calculators tell you anything from your carbon footprint to how many pennies are in a jar!
webmath.com - You can put in any math problem and it will show you step-by-step how to do it.