The documentation for GameMaker is divided into four parts:

Using GameMaker

This section describes the basic use of GameMaker. 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.

The following topics exist in this section:

Introduction
Installation
Upgrading from the Lite Edition
Getting Started
The Global User Interface
Defining Sprites
Sounds and Music
Backgrounds
Defining Objects
Events
Actions
Creating Rooms
Distributing your Game

Advanced use

This section describes the more advanced aspects of GameMaker. It deals with paths, fonts, time lines, scripts, and techniques for creating tiled rooms and using views in rooms.

The following topics exist in this section:

Advanced User Interface
More about Sprites
More about Sounds and Music
More about Backgrounds
More about Objects
More Actions
Constants
Trigger Events
Including Files
More about Rooms
Fonts
Paths
Time Lines
Scripts
Extension Packages
Exporting and Importing Resources

Polishing your game

This section deals with how to turn your project into a finished game. It describes how to add help information to your game, how to set the various options for your game and how to create stand-alone games that you can distribute to others and can be run without the need for GameMaker.

The following topics exist in this section:

Game Information
Global Game Settings
Speed Considerations

The GameMaker Language

GameMaker contains a built-in programming language. This programming language gives you much more flexibility and control than the standard actions. This language we will refer to as GML (the GameMaker 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.

The following topics exist in this section:

Language overview
Computing things
Game play
User interaction
Game graphics
Sound and music
Splash screens, highscores and other pop-ups
Resources
Changing resources
Files, registry, and executing programs
Data structures
Creating particles
Multiplayer games
Using DLL's
3D Graphics