WordPress MU

Hello,

I downloaded a wordpress template, installed and activated it.
I wanted to do some modifications, so I updated the
sidebar2.php (left hand side), and the sidebar.php (far right) side.
I also updated the index.php and added text for the home page.

URL:
http://eastcoasttechwriter.ca/wordpress/

If I create a new page (example expertise), then do a preview, the text is not updated, I just get a view of the index page, but with a different id.

URL:
http://eastcoasttechwriter.ca/wordpress/?page_id=25&preview=true&preview_id=25&preview_nonce=e07240aa9d

Can someone please help me out of my mess?

Like i said in the other thread - to change the text of the page, you do not edit the theme itself.

Handy links:
http://codex.wordpress.org/Using_Themes
http://codex.wordpress.org/Pages
http://codex.wordpress.org/Blog_Design_and_Layout