How does one get started with procedural generation?

You should probably start with a little theory and simple examples such as the midpoint displacement algorithm. You should also learn a little about Perlin Noise if you are interested in generating graphics. I used this to get me started with my final year project on procedural generation.

Fractals are closely related to procedural generation.

Terragen and SpeedTree will show you some amazing possibilities of procedural generation.

Procedural generation is a technique that can be used in any language (it is definitely not restricted to procedural languages such as C, as it can be used in OO languages such as Java, and Logic languages such as Prolog). A good understanding of recursion in any language will strengthen your grasp of Procedural Generation.

As for 'serious' or non-game code, procedural generation techniques have been used to:

• simulate the growth of cities in order to plan for traffic management
• to simulate the growth of blood vessels
• SpeedTree is used in movies and architectural presentations

Procedural Content Generation wiki:

http://pcg.wikidot.com/

if what you want isn't on there, then add it ;)

Procedural generation is used heavily in the demoscene to create complex graphics in a small executable. Will Wright even said that he was inspired by the demoscene while making Spore. That may be your best place to start.

http://en.wikipedia.org/wiki/Demoscene

Procedural content generation is now all written for the GPU, so you'll need to know a shader language. That means GLSL or HLSL. These are languages tied to OpenGL and DirectX respectively.

While my personal preference is for Dx11 / HLSL due to speed, an easier learning curve and Frank D Luna, OpenGL is supported on more platforms.

You should also check out WebGL if you want to jump right into writing shaders without having to spend the (considerable) time it takes to setup an OpenGL / DirectX game engine.

Procedural content starts with noise.

So you'll need to learn about Perlin noise (and its successor Simplex noise).

Shadertoy is a superb reference for learning about shader programming. I would recommend you come to it once you've given shader coding a go yourself, as the code there is not for the mathematically squeamish, but that is how procedural content is done.

Shadertoy was created by a procedural genius, Inigo Quilez, a product of the demo scene who works at Pixar. He has some youtube videos (great example) of live coding sessions and I can also recommend these.