Customizing categories display

[ELarrabee]

Though the control panel I have set the categories list to display in the single column mode. I set the sort order of categories to 0. The result is that I have two lists of categories - one at the top and one at the bottom of the center page.

Where can I edit the logic/layout of these category links?

-ed

[gjh42]

The categories-tabs menu runs horizontally at the bottom of the header, and you can turn it off in Configuration > Layout Settings, or style it in your stylesheet.
By "bottom of the center", do you mean the main list of categories? Again, you can style them in your stylesheet.
A link to see your site will make it easier to advise.