As I've worked on PromoStandards-related projects over the past few years, I've found some resources to be particularly helpful. I thought I'd share some of the in this post.
The Official PromoStandards Web Site
http://promostandards.org/
I turn to the official site for the latest services documentation, WSDLs, supplier service information, and more.
The PromoStandards Service API
http://promostandards.org/documentation/service_api/
The service API is a RESTful, JSON-based API that makes it possible to query the PromoStandards database to get lists of participating companies, supported services, endpoints, and more.
The PromoStandards LinkedIn Group
https://www.linkedin.com/groups/8620628
The PromoStandards LinkedIn Group is the place to go to keep up with PromoStandards. Events are posted here, and it's also a great place to ask technical questions.
The PromoStandards Github Repository
https://github.com/promostandards
The PromoStandards team maintains a Github repository. Use it to access sample code, including client code written in PHP, C#, Java, and .NET.
What is Promo Standards?
https://www.youtube.com/watch?v=vFmJxwrgLwE
If you're new to PromoStandards and trying to make sense of it all, or need to quickly bring someone up to speed on what the initiative is all about, check out this video. It was created by David Jackson at Sweda.
Paw
https://paw.cloud
Paw is an advanced API tool for the Mac. I use is to test PromoStandards services, develop and test my own APIs, and more. Highly recommended!