Worldbook Online Advanced (Ask Librarian for Home Log-in)
http://www.worldbookonline.com/advanced/home 
World Book Advanced integrates primary and secondary source databases in a single search. Resources include encyclopedia content, e-books, images and sounds, research tools, and primary source documents.

Encyclopedia Britannica Online (Ask Librarian for Home Log-in)
http://www.wiscat.net/homepages/CustomerWide/ValidateGlobalIP.asp?cuid=stwi&lid=stwi&dataid=32&term=
Start with an encyclopedia for solid background information and selected links to the Web on your topic. This site consists of a fully searchable and browsable collection of authoritative references, including Britannica's latest article database, hundreds of articles not found in the print Britannica, Merriam-Webster's Collegiate Dictionary (Tenth Edition) and Collegiate Thesaurus, the Britannica Book of the Year and thousands of links to other World Wide Web Sites. Note: you can pre-check which areas you would like to search in; the default is all areas.  There is a Spanish translation tool (available in Encyclopedia Britannica and Compton's only) where after you have looked up an article, you can click an orange Spanish Translator button at the top of the article.

Student Research Center
http://www.badgerlink.net/