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
Blender
3D Animation
Source FilmMaker
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"