Make a selection from the index menu in the left-hand frame, and the links to resources pertaining to that selection will appear in this window. Then, click on one of the links in this window, and that resource will appear in this window.
If you want to investigate a new item in the index menu, simply click on that item, and the resources pertaining to your new selection will appear in this window.
To escape from the frames altogether, click on one of the selections in the bottom frame.
Finally, if you want to view these instructions again, click on [Viewer Instructions] in the bottom frame.