I have been working with various Amazon APIs related to selling items on Amazon for several years now. As many developers know, Amazon's documentation and support is sorely lacking and can be extremely inconsistent. I'm going to be providing information I've gleamed over the years on this site to help prevent others from wasting days trying to sort out their system.
As a few notes, I'm a developer for one of the larger sellers on Amazon. I have experience with the APIs relating to managing seller listings on Amazon, including FBA (FWS), and their eCommerce / Amazon Associates web service. I code in PHP, so all my examples will be in that language.
