The user manual is divided into three parts with the aim of getting you introduced to the interface and basic workings of GameMaker Studio 2
An online hub for essential resources for game developers. Guides that also cover topics like business, distribution and marketing.
GMLscripts.com provides the highest quality GameMaker scripts available. These GML scripts are completely free for use in your GameMaker projects.
Amazon Dev Blog
From Amazon's development blog, learn the GameMaker basics from gamedevs like Nathan Ranney (@ratcasket) and Alejandro Hitti (@AleHitti).
From Reddit, a comprehensive list of helpful tutorials, tricks, how-to's and useful resources for use with GameMaker.
Xor GameMaker Shaders
Xor uses GameMaker Studio for making games and shaders. As a self-taught programmer, he created this website to help others learn about shaders.
DaveTech shares writing game development tutorials and tools for making games. He's a developer who has a great collection of work.