This web site has a growing number of sub-sites, each indicated by a picture
or graphical icon arranged in the navigation column on the left. If you
hover your mouse over the icon, a popup message will describe the sub-site.
You can always identify which sub-site you are in by the title on the
page and by matching the icon in the upper left corner to the icon in the
Every sub-site serves a different purpose and is organized somewhat
differently. Most of them have a tabbed menu bar across the top to
indicate the choices available within that area. If you move your
mouse across the tabs, the descriptive text underneath will explain what that
option or choice does.