There has been quite a lot of coverage of research sponsored by Google and carried out at the University of Maryland which looked at children's use of search engines, for example in the Herald Tribune, and the Independent. The problems that children have are identified, and more use of, e.g., graphical search input, is suggested. Through, um, googling, I found out that the project is called When Children Search: Understanding What They Do and What They Could Do with Google Search and the principal investigator is Allison Druin and I found an interesting site about her research group , but not yet an academic report on the research. In the New York Times, a school librarian pointed out that information literacy should be an answer, not just making search intrfaces easier.
Photo by Sheila Webber: GUM shopping mall, Moscow, December 2009