1. xtramath.org - This site allows students to work on their math facts and tracks their progress
2. abcya.com - A site with math and language arts
3. tenmarks.com - Another math site for students to practice their math facts
4. http://oxfordowl.co.uk/ Free ebooks for children (good quality with great illustrations). You can have audio on or off as needed (math is also available on this site).
5. http://www.wegivebooks.org/ This site is by far one of my most favorite sites I have recently found. This doesn't just have online books, but we're talking great quality books that weren't just created for the actual site. You can start your own virtual library and save books. This is great if you teach a lesson later in the year, but you see a great book to go with the unit before you're actually ready to use it.