The following Web sites contain examples of WebQuests used in various schools. The more familiar you are with other WebQuests, the easier it will be for you to design your own or to modify existing WebQuests to meet your needs.
University of Richmond
On this site, you'll find WebQuests for all grade levels on subjects including history/social science, science, English, foreign languages, and art.
Germantown Elementary School, Illinois
This school has WebQuests for elementary school students related to science, social studies, language arts, and visual arts.
Arizona State University West
Elementary and middle school WebQuests are featured here -- including vocational WebQuests like CareerQuest and even professional development WebQuests for teachers.