STEP 5: How up-to-date is this site? If we scroll down to the bottom of the page, we see that the sponsor of this site is the U.S. Department of Energy, and that the information was last updated on July 31, 2003.
This is very useful information. Otherwise, we would have no idea how old the site is; a problem with many that aren't dated.
As you evaluate a site always look for a copyright, or last update notice, often found at the bottom of the first or last page.