could someone help me understand the way wordpress creates rss feeds. i need to figure out what the address will be to my feeds so that i can put them up on the website so that visitors who are not very tech can easily access them.

my experimental feed is here.

is the address needed by a feeder - thundebird for example - just that address + /feed.bla or something. i tried /atom.xml but that didnt work and i sort of got stuck.

thanks in advance

Wordpress creates the RSS feed with PHP. The PHP script for RSS 2.0 feed is called wp-rss2.php and is located at the Wordpress directory. So in your case the address would be:
http://www.organicbmx.astahost.com/wordpress/wp-rss2.php

You can link the file directly just like any URL and the browser/ RSS reader should recognise the file from the file mime type even if the file extension isn't .rss or .xml.

In addition to that you might wish to add a link to the html header. The code would look like this:

<link rel="alternate" type="application/rss+xml" title="RSS 2.0" href="wp-rss2.php" />.

Intelligent browsers (Opera, Firefox) regocnise this and offer the user an easy way to subscribe to the feed. It's a bit hard to explain, it's better that you try it out yourself.