The website for this museum (in San Francisco) has lots of great learning resources. There's an extensive library of videos, a nice collection of lesson plans, and a few games and interactives. There are also lessons on keeping a science notebook, which can be applied to other science curricula and programs.
Online, interactive program for learning music reading and theory.
This non-profit organization offers over 100 free self-paced, online, college level courses.
This online math program is designed to help students with math problems (including dyscalculia.)
This hands-on grammar curriculum includes CD ROMs, teacher manuals, and games for learning gramma
Online, super-hero themed science games for elementary and middle school levels.
This program includes videos, worksheets and quizzes for history learning in jr.