Hi,
Congratulations! It's great that you will be going to the national science fair. Here is a reference that describes how to format scientific references from various sources. For journal articles, I usually use the format: W. Nilsen, Bioessarys, 25, 1147,(2003), as it saves space.
I thnk this is the description of the report you will be writing:
http://cwsf.youthscience.ca/project-report
I looked for a suggested bibliograhy format, as this is sometimes included in the directions, but did not see anything, so you should select a format and make sure all of your references are consistent.
Be sure to read all of the rules and regulations for entering this fair and follow all of the directions to the letter.
Let us know if you have any other questions.
Donna Hardy