When conducting a search online the first option is usually Google. While Google scours the entire web for information, SweetSearch, made by Dulcinea Media, narrows the search for younger students and eliminates ads and inappropriate content. SweetSearch searches roughly 35,000 websites that are all vetted by research experts, librarians and teachers. These sites are constantly being evaluated by the SweetSearch staff in order to provide the best results for your students. Plus, the search results are constantly evolving to provide credible sources from the Library of Congress, the Smithsonian, PBS, and university Web sites.
Here is a short tutorial on using SweetSearch.