Project ideas along with the whys and hows of creating a great project. Sponsored by the Discovery Channel.
Science Fair Central

Learn what sets the great projects apart, and tips for good displays.
Successful Science Fair Projects

Breaks down the process of completing a science fair project and provides many links to other sites. Sponsored by the Internet Public Library.
Your Science Fair Project Resource Guide

Do you have a winning idea? – Visit this site to sign up for the 2013 Google Science Fair, and info on the winning projects and students in 2011 & 2012.
Google Science Fair

If you're looking for help getting started, just click the SPIN button for great ideas! Or, Browse By Subject until you find a topic that noodles your noggin.
Dragonfly TV Science Fair

Help, advice, and plenty of ideas, plus a look at some of the more popular science fair projects.
Science Fair Project Ideas

Great ideas for science fair projects from the US Geological Survey.
USGS Science Fair Ideas

Ideas for science projects with an agricultural flavor.
US Acricultural Research Service Sci4Kids

Lots of links to energy-related project ideas.
EIA EngergyKids Science Fair Experiments

Animated pals Newt, Enrico, and their friends help you learn about nuclear energy, and give you some experiments to try.
US Dept of Energy Science Projects

Find a project of interest in this alphabetized list of ideas.
Science Fair Adventure Projects

Fact Monster presents Science Fair Projects: Understanding and Using the Scientific Method - whys and hows of science
Science Fair Projects - Understanding and Using the Scientific Method

Some basic but interesting project ideas from SMS Marketing:
SMS Science Fair Project Ideas

From the Science Is Fun webpage, a whole bunch of home experiments to use for science fairs.
Science is Fun Home Experiments