You can find the standard affiliate banners along with linking instructions here:

Affiliate Program

I would avoid using merchant banners specifically, since it's difficult for you as an affiliate to track and edit banners for specific products. Also, based on conversations with some of our older affiliates, ads that lead to the site homepage perform much better than specific product ads. Email me at jasonk@renderosity.com if you have any other questions.

You friendly neighborhood Marketing Manager here at Renderosity.

www.renderosity.com