This is an excellent site that contains a multi-disciplinary approach to world history. Any subject area can benefit from this powerful, free resource.
Edutopia has great information about all aspects of teaching and learning. This is one of my top go-to resources.
a good place to start your research
Everything you ever wanted to know about English grammar but were afraid to ask...
...everything you ever wanted to know about writing for class, but were afraid to ask...
Free literature...that's right...I said FREE.
international writing site
a graphical dictionary & thesaurus