This website is a great resource to the visual learner and the free version allows you to create a visual concept map posting website links and videos. You can also make your visual map public and have multiple people working on the same map.
This website is the National Association of Special Education Teachers. I think it's a great resource for special education teachers and general education teachers. There is information about conferences, professional development, IEP development, resources, special education law, and so much more.
TenMarks is an excellent resource to use for Math. This website is aligned with the Common Core Standards and provides students with excellent practice and understanding of each standard. The classroom teacher can sign her class up on the site and provide each student with a username and password. From there she can assign different problems for the class to solve based on the skills they are learning or have already learned. Each question has a video lesson and hints to support the students if they are struggling. TenMarks also automatically provides the students with an intervention or a re-teaching video if they continue to struggle with a concept. It also provides the teacher with reports on the progress of each student. This is something that my fifth grade colleagues and I started this year and it has been great!
Empowering and connecting teachers, administrators, and parents with innovative solutions and resources to better education. This site has ideas for group learning and motivating students.
This is the blog of a second grade teacher who provides insight on various common core standards and shares many resources related to the common core. She provides 2nd grade writing rubrics related to the common core standards.
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).