Science Fair

Their site says that they have hundreds of science fair ideas for every level.

Chemistry Science Fair Projects

Science Fair Adventure

Science Fair Projects World

PDF files that contain multiple Science Fair projects to examine

700 experiments in pdf form to browse:  Opens on new page

If you would like a comprehensive document that describes science fair procedure, the following was largely pirated (borrowed, stolen, ripped off) from Anne Arundel County Public Schools in Maryland (who did a wonderful job) and placed in its current form by a phantom entity.  The original document is a great guide for elementary school science projects, but it also has very good information for everyone.  It is formatted in MS Word, but it is a formatting nightmare to change, so good luck if you try to re-format it.   

Suggested Science Fair Projects

Here are over 50 suggested projects with methodology suggestions as well