Here is an excellent site to get started thinking about science fair topics and putting together science projects
The Science Buddies website "offers a large online library of project ideas and starter kits, as well as an online forum in which students can ask questions about their projects and get answers from scientists and engineers who volunteer as e-mentors" (Association for Middle level Education)
This site lists several excellent project ideas for elementary, middle school and high school levels.
Another good site for science fair project ideas.
Having problems finding a contact source? Here's a site that may help!
Please Note ... There are plenty of resources to assist students in selecting science project topics... Should the above sites not provide desired topics, students should research additional sites and/or refer to the libraries.