1 - Go to your Flickr page

2 - Click on "You" and select "Your Profile"

3 - When that page has loaded, click on "• Edit your Profile" on the right hand side of the screen

4 - In the box "Describe Yourself..." copy and paste either of the following bits of code:

AP link with image;

Code:
<a href="http://www.amateurphotographer.co.uk" target="_blank">
<img src="http://www.amateurphotographer.co.uk/images/ap_logo.gif"></a>
AP link text only;

Code:
<a href="http://www.amateurphotographer.co.uk" target="_blank">Amateur Photographer</a>
5 - Click on "SAVE IT" at the bottom of the page