You will need to purchase a trifold display board (I know Wal-Mart has them).  On this, you will paste each of the six steps from the Scientific Method, which you used in your experiment.  You can write them out, or use a presentation software so that you can print the pages out easily.  Use my notes and example presentation below as a reference for how each of the parts should look. The best website I have found for information on science projects is Science Buddies.  Also, you can view the final rubric here.

Notes

Example Project