There are so many great sites on the Internet, you could spend entire days flipping from one to the next. I have found it is fun to save my favorites in Furl. Sign up and start an account, then you can take your bookmarks with you everywhere you go! I have a section called favorites, one called lesson plans, digital cameras, etc. It has come in handy so very often.
Another great site I have shared with many students is David Warlick's "Citation Machine". This website comes to us at a time when plagiarism is out of control and spiraling... I send my students to this site to make it easier for them to cite their sources. When creating a research paper or a simple report, I have students start a word processing document that is just to record dates and websites they have visited or reviewed for their paper. At the end of their work when they are ready to publish, they simply go to the CITATION MACHINE website and create thier citations in either MLA or APA format. This is my little contribution to fighting plagiarism on the Internet.
Some students enjoy using Student ABC - MLA Citation. They say that it is a little easier to use.
Speaking of plagiarism. Don't send memos to schools in your district with an article on plagiarism and tell them to duplicate it unless you have permission from the author! That's just silly....
On a final note - check out this website every Sunday so that you will never be alone.