Mel Bose The Terrain Tutor has a Kickstarter.
Terrain Essentials is a planned book detailing how to build terrain and a book that I have no hesitation in recommending. I have watched most (there are quite a few) of Mel's videos and look forward to seeing his first book.
For full details of how you can support this Kickstarter (which was fully funded in less than seven hours) see this link.
Good luck and thank you for all the inspirational videos.