Resources
Tools
2D Art
Photoshop
Photoshop ...
Gimp
Gimp Free & open source image editor.
Article related to this to make it so that you can use it as replacement for PhotoShop Gimp as Photoshop
Asesprite
Asesprite is an animated sprite editor & pixel art tool.
3D Modelling
3ds Max
3ds Max is a 3D modeling and rendering software by Autodesk for making 3D animations, models, games and images (formerly 3D Studio and 3D Studio Max)
Blender
Blender is a free and open-source 3D graphics software used for creating animated films, visual effects, art, 3D printed models, interactive 3D applications and video games. By Blender Foundation.
3D Animation
Source FilmMaker
SFM on Steam Movie-making tool built and used by Valve to make movies inside the Source game engine. Because the SFM uses the same assets as the game, anything that exists in the game can be used in the movie, and vice versa.
Game Engines
Twine
Twine is an open-source tool for telling interactive, nonlinear stories.
RPG Maker
RPG Maker is an commercial tool for creating top-down 2D role-playing games.
GameMaker
GameMaker is best suited for 2D games, it can be quite powerful and it has less steep learning curve compared to Unity.
Unity
Unity can be used to make both 2D and 3D games alike, previous experience with programming is recommended.
Assets
Graphics
SFMLab Models, textures, maps, guides and NSFW resources for SFM.
Music
SFX
Learning
Tutorials, articles, books, that sort of stuff.
Modding
Scripting TES / Fallout
Creation Kit Wiki for Skyrim & Fallout 4.
Cipscis Scripting tutorials for Fallout 3/NV & Skyrim.
Misc
Creating a Loading Screen for Skyrim
How to make your own Skyrim patches
Game design
Gamasutra "The Art & Business of Making Games"