From Valve Developer Community

Download and Installation | Frequently Asked Questions | Release Notes
Modding
|
Creating, organizing and releasing your Source project
|
Level Design
|
Maps are the 3D worlds where everything comes together
|
Programming
|
A mod's C++ code defines the way its world and game rules behave
|
Scripting
|
Scripting can be used for adding new functionality or logic to entities
|
Modeling
|
Models are the detailed 3D objects that appear in the game world
|
Materials
|
Textures and shaders are combined in Source to create materials
|
Sounds
|
Quality audio adds a fourth dimension to your world
|
Particles
|
Effects like smoke, sparks, blood and fire are created with particles
|
Choreography
|
Direct your digital actors' performances with choreographed scenes
|
Filmmaker
|
Create movies inside the Source Engine
|
Tutorials
|
Step-by-step guides on a variety of topics
|
Technical
|
In-depth discussion of Source's features
|
Glossary
|
Explanations for terms you may encounter
|
Third-Party Tools
|
Useful developer tools created by the community
|
I/O System
|
The I/O system is the backbone of most levels in Source based games/mods
|