Excellent, thank you. I've add to the OP.
Printable View
New news to me, Mike Shea aka SlyFlourish has released two of his books via CC-BY-NC-4.0 so now everyone can read them for free. I've only skimmed both of them, but have often read and linked above to his blog were many of the ideas in his books are also discussed. I will update the resource with links to these two online versions of the books;
Dungeon Master Tips (slyflourish.com)
The Lazy Dungeon Master (slyflourish.com)