I just installed the Amazon Item plugin for Wordpress but I have a question about the configuration. How does a AWS Access Key look like and what's then an associate tag?
You need to apply for AWS access key, look to the link named AWS service. An asso tag is another one you created in Associate central. What plugin you are using?
Amazon Item sounds like ours, hehe. The AWS (Amazon (Associates) Web Services) key is needed to pull the product data from the Amazon database, you can register for one at http://aws.amazon.com/ (scroll down a little for the create account link) The Associates Tag is you Amazon affiliate ID, e.g. yourchosenid-21 which is needed to credit any sales to your associate/affiliate account.