This is a great website, have made great use of it!

http://www.pbs.org/teachers
This is a great website that I use to reinforce skills I'm teaching in all subjects.
http://www.starfall.com/
Excellent source for young students learning to use technology very inviting and user friendly. Students engage in learning reading skills while having fun at the same time.
http://coolmath.com/
This website has fun games that address all disciplines, students don't realize they're actually learning while playing games.
Reading Matters http://www.pcboe.net/les/elderweb/
This website was created by a peer teacher to enhance the reading instruction within our reading series. The website contains a vast amount of resources that aid reading instruction.
I want to add one more that I use to use daily, but have gotten away from it.
Spellingcity.com, this is a great website for spelling skills.