Theme a taxonomy terms page
You could use panels. Heres a good guide to setting up page manager with panels.

http://drupal.org/node/1582906

or you could use templates...


taxonomy-term--[vocabulary-machine-name|tid].tpl.php
base template: taxonomy-term.tpl.php

  
  Theme hook suggestions are made based on these factors, listed from
  the most specific template to the least. Drupal will use the most
  specific template it finds:

taxonomy-term--tid.tpl.php
taxonomy-term--vocabulary-machine-name.tpl.php
taxonomy-term.tpl.php

  
  Note that underscores in a vocabulary's machine name are replaced by
  hyphens.


See: http://drupal.org/node/1089656