SEO Text at bottom of specific pages

Hi there,

I plan to include a text that describes the overall forum and certain important categories (mainly for SEO purposes). The text should be below the content (footer?) - like for example at at the bottom of the main page.

I want certain text versions to be shown

  • on the mainpage (bottom)
  • in certain categories / forums
How can I do this? Many thanks for your help!

Example (from an E-Commerce-Site):

Bildschirmfoto 2013-02-26 um 22.12.29.png