Credit card logos:
http://www.e-onlinedata.com/support/cardlogos.php
Paypal Logos:
https://www.paypal.com/us/cgi-bin/webscr?cmd=xpt/cps/general/SolutionGraphics-outside
If your website template contains a %SITE_MESSAGE% include code you should be able to insert the html code into your Site Settings page of your store admin area. If you insert the code into your Site Settings page and you don't see anything on your site, or you want the logos in a different place you should contact your template designer for help.
