This is a great website to preview books and look up Lexile levels to see what is appropriate for your students. It is geared toward Middle school. Students can use this site to make their own book trailers. A nice alternative to book reports.
This is a great math website for elementary and middle school students. It contains a lot of information along with fun activities, games, worksheets, and quizzes.
This site--English pedagogy guru Jim Burke's ning--is a treasure trove for middle school and secondary English instructors. Joining requires verification of your relationship to a learning institution. The site is well organized, allowing me to browse by general topics and within forums. It's a virtual teacher's lounge, allowing for quick takes on strategies for teaching any number of things, or in depth discussion on the viability of Literature Circles for Shakespeare study. I could easily get lost in the forest of great ideas here.
This website is accessible for all ages, elementary, middle and high school. It has four main tools and services: The Renzulli Profiler, Differentiation Engine, Grouping and Reporting Tools, and Personal Success Plan. The Renzulli Profiler uses a strengths based assessment to find out a student's top three strengths, interests, and learning and expression styles. The Grouping and Reporting Tool then takes these results and uses them to group students.
This is a site I use all of the time where I tutor. It is geared mostly towards elementary and lower middle school students. I go straight to:
http://bedtimemath.org/category/daily-math/
and use any of the problems posted daily as a warm-up for students. The problems are creative, real-world and entertaining. Read about the world's fastest-moving hot tub:
http://bedtimemath.org/fun-math-carpool/
This link to the Oxford English Dictionary is an invaluable resource for Middle School ELA and Secondary Ed English teachers. I can see it as a frequent "go-to" site for Student Researchers, providing more interesting content than a standard online dictionary. Because the OED is concerned with word origins, I believe it would be helpful in creating bridges with ELL students as well, giving them a chance to see the linguistic contributions their language has made to ours. Check out the link in the lower center column for teachers and students (resources and lesson plans).
This website uses sports such as basketball, baseball, and soccer to help students learn mathematics in elementary and middle school. In addition, there are logic and jeopardy games.