From YoYoGames Wiki
Designing Games with Game Maker
Written by Mark Overmars
Version 8.0 of Game Maker has a large number of improvements over version 7.0. In this section some of the most important changes are described.
This section describes the basic use of Game Maker. It explains the global idea behind the program and describes how to add sprites, background and sounds and how to define objects with events and actions and how to add them to rooms.
This section of the help file gives you information about the more advanced aspects of Game Maker. It deals with paths, fonts, time lines, scripts, and techniques for creating tiled rooms and using views in rooms.
When you want to distribute your game you had better make sure that it has all the ingredients that make it a great game. Besides the game itself this means that you should provide game information, set the correct global game settings, and take care of speed. This section gives you information about these aspects.
Game Maker contains a built-in programming language. This programming language gives you much more flexibility and control than the standard actions. We will refer to this language as GML (Game Maker Language). In this section we describe the language GML and we give an overview of all the (close to 1000) functions and variables available to control all aspects of your game.