I did not want to use categories for the time being, so I suppressed the display so I can enable it later when I have more entries.
In the sidebar.php I did this:
<!-- Categories information is disabled. Uncomment and fill in your details if you want to use it.
<?php wp_list_categories('show_count=1&title_li=<h2>Categories</h2>'); ?>
<?php /* If this is the frontpage */ if ( is_home() || is_page() ) { ?>
-->
On my homepage, this works just fine; you cannot see the categories list on the sidebar at all. However, all the above code and commentary--which I thought I'd hidden--shows up in the sidebar when you go to the archive page. How do I get it so it is hidden on the archive page, too????