Admin ToolBar not being displayed at top of site

It sounds like your theme does not use wp_footer() the way it should. That function should occur right before the closing </body> tag. The admin bar runs on a hook fired by that function. Without it, I get exactly what you describe.

For reference, in Twenty Thirteen, it looks like this: http://core.trac.wordpress.org/browser/trunk/wp-content/themes/twentythirteen/footer.php