Chinese
This website by California State University offers a comprehensive list of online resources for learning Chinese.
http://www.csulb.edu/~txie/online2.htm
French
This adorable Winnie the Pooh website includes activities, coloring pages and stories, including "The Little Prince".
http://www.abcdespetits.biz/
Kidadoweb includes an amazing list of websites tailored for kids. Many of the websites include videos and activities.
http://annuaire-enfants.kidadoweb.com/sites-pour-enfants/heros-tele/index.html
Italian
Bambini includes a slew of learning materials including songs, nursery rhymes, worksheets, games and stories.
http://www.bambini.it/
Russian
This great blog features fairy tales, nursery rhymes and songs for kids.
http://russianforkids.blogspot.com/
Spanish
This webpage from the University of Northern Iowa includes a directory of webpages, some free and some not free, for children.
http://www.uni.edu/becker/children.html