I'm always on the look out for sites that provide a safer research experience for elementary students. (Note: You'll never hear me say "kid safe". Nothing is totally safe on the internet. We always have to provide instruction in digital literacy and searching skills.)
DK Find Out is a site I learned about on the "i Teach with Technology" blog. It looks like a great resource for elementary student research. It's very visual and all the searches go to DK webpages so you don't have to worry about the sites that it links to.
Students can search by keyword or phrase with the search box or explore through a visual subject index.
I always test new search sites using the keyword "chicks" (Lots of elementary students watch chicken eggs hatch and search for "chicks" rather than "chickens". If you put "chicks" in some search engines, chicken results is NOT what you're going to get!) You can see that DK Find Out returned lots of results all dealing with birds. :-)
All of the pages are arranged the same... text on the left with an interactive picture on the right (click the labels on the picture to learn more). There's also a little quiz, links to more information about the topic and sometimes even an audio file to listen to.
Check it out and let me know what you think in the comments!