Yea, you are right, the info is out there but its spread in all sorts of topics and places, so seems good to have it here as well.
Best source in English in my humble opinion was Jack Sweeney. His books were translations of many Chinese authors focusing on case studies. Some of them were not great, some were awesome. There are 3-4 cases of there around the net as well. His QMDJ books can't be bought anymore I think and they were expensive when they were sold. They could be found around the net in file hosting sites, but the copyright is unclear so seems wiser to not post links.
JY has good books, in my humble view some fundamental rules doesn't exist in there, yet some of the books are very good for what they are suppose to do. Forecasting methods series and the 100 combination, the compendium has a lot of good info as well. So its good source, but may need something more to get it working.
Dr Khim Goh seemed to be a good source, I stopped following there some time ago, so I have no idea how it is now, but there were free videos that had interesting rules that someday if I have the time will try in more details. Had great hopes for the material there, but there is too much going on to fully test it combined with the current info, so can't comment how it has developed there and may not be able to focus on it in the near future, anyway.
There are some books more focused on daoistic shamanism I guess?Not sure how to define it, but it looks at the system in great detail as practiced by religious Daoists and its very different. Parts of JY stuff seems related to there, yet from what I have seen I don't think any of that will work great, can't recommend anything for the shamanistic part, currently. Though nothing wrong with getting familiar with it, there are these few sources, currently.
Ren mentioned few interesting sources as well, search around the net can show few more. That is more or less all we have I think, at least I can't think of much more. There are some seminars in Russia with videos in youtube, but you can find them by searching youtube. There were also some translated videos, I liked them, they can also be found there etc. Few good blogs, some may need archive.org to see, and scattered info around the forums.
Check Vimeo too, they had many videos from a school of QMDJ too, I don't know if still there.