I assume you're asking about affiliate accounts / adsense with google? On Amazon affiliates are known as associates; scroll down to the botom of the Amazon page and look for the associates link under the make money with us heading. Click this and follow the sign up procedure. Many retailers and service providers on the internet operate affiliate programs, if there isn;t a link on their site they can sometimes be found by googling the trading name and affiliate. You'll often find they are run through third party affiliate program managers like commission junction.
For adsense google and click sign up now! It helps if you have some web presence like a webste, blog (adsense is well integrated with blogger) or hubpages, of course! This applies with many affiliate programs which want to know where you'll be promoting them.
Hope that helps!