Hi, please treat me like I'm stupid because, well, I am -- you'll need to speak slowly using small words :)
I use Mandigo as a theme, if that matters, and I recently upgraded to WordPress 2.3 at http://tv-eh.com. Everything went well until I realized I have an URL issue with categories.
For some reason, pre-upgrade, my categories were called "tags." For example, http://www.tv-eh.com/tag/cbc/ was what lead to the CBC category. Now, that leads to an error message, and http://www.tv-eh.com/category/cbc/ is what works. The problem of course is that the site's been around for a while, search engines have indexed with the "tag" URLs, people have linked to the "tag" URLs, etc.
I've played around in the WordPress control panel with the Options-Customize Permalink Structure to fix it, and in Cpanel to try to do a redirect from /tag/* to /category/* but nothing is working.