I have started an on-line book of recipes for building hypermedia APIs with the Mason (hyper)media type. It is very much work in progress but hopefully I can add one or two recipes a week on my daily train commute to and from work.
The book source is hosted on GitHub and is made available on-line at GitBook in various formats. Later on I may host it another server depending on how GitBook turns out to work with - but so far it has been a nice experience.
You are most welcome to add issues, fork it and send me pull requests for improvements.