If you need help learning and memorizing facts, quizlet.com has online flashcards that are quite useful.
You can use pre-made flashcard sets, you can modify existing flashcard sets, and you can create your own!
You can of course upgrade to the Plus version for $10.00 a year. The plus version allows you to upload images and allows you to create an unlimited number of groups (probably suited for teachers)
The free version is pretty useful as-is though.
~posted by Andrea from Notes from a Homeschooling Mom