This first site is a great database to help kids guide their research. It has search engines, external databases and searchable archives that should be a great help.
KidsInfo can be a very useful site when navigated with the help of a parent/guardian or older sibling/friend. This particular part of the site has great information on world geography and "Country Facts".
What a neat site this one is! Mama Lisa's World has a great database of kids songs, lullabies and nursery rhymes from around the world. Even better? It is translated into French and Spanish. If you child is seeking information about music from a particular country, this site will prove very useful.
In that same vein, Sara-Jordan.com is another site with songs and reference to things around the world. This specific link talks about foods from many countries.