I just read a great blog called web home schooling which had an article with some homeschooling website recommendations. And I quote:

My strong recommendation for those homeschooling and using the web is to check out the following.

 Time4Learning’s web-based online curriculum.  They have great interactive lessons for middle school, elementary school, and even preschool.  It’s highly interactive and full of animation and multimedia. Whereas some curriculum are just lots of text with an occassional video or animation, Time4Learning is an interactive experience.  All those tough math concepts seem simple when they’re explained in such alight-hearted manner.  Who says fractions has to be hard? Their great multimedia lays it out so simply.  Give it a try.  Time4Learning is a great homeschool partner. They let you sign up month to month and start and quit at any time. Start by looking at their lesson demos.
 

 Number 2 choice - Time4Writing.  If you are like me, you find some subjects hard to teach.  One of the hardest is writing skills, especially when the kids get into middle and high school.  Expectations are so high. And my kids just don’t react well to my correcting their writing. Want help?  This isn’t a “how to”, it’s an online tutoring course where they work directly with your student teaching writing skills every week and giving one-on-one feedback.  You get the same tutor for the whole eight week course which the kids really like. It’s definitely worth taking Time4Writing’s writing classes. They have sentence writing, paragraph writing, essay writing (these are for writing tests and college essays), and research paper writing.
 
 
Number 3 choice - Fun Building Vocabulary. This is not really a curriculum choice but a fun collection of vocabulary games. Vocabulary is Fun is a leading vocabulary website worldwide with the best flash online word games.  The vocabulary games include an online word search, an online crossword puzzle, and hangman online (their version is called HangMouse).  Users choose the vocabulary list that the online word game will use in the word game. So have some Fun Building Vocabulary.  
 
 
Number 4 Choice - Spelling City. This spelling program should be used by everyone. I would have put it first but I’m not a huge believer in the importance of spelling skills.  Despite that, now that I’m using this site, I’ve returned to having spelling as part of our weekly routine.  You know what’s really cool, check out how the vocabulary site’s science songs have put their vocabulary/spellinglist on SpellingCity.
 
 
Number 5 choice - This learning games website is really what it sounds like.  But they have the best collections.  For instance, they have keyboarding games, memory games,  science songs (also integrated with vocabulary lists), and math learning games.