Here is all three part of my raymarching series. I hope this 5 hours could be a nice and solid start for you in this topic. It requires at least basic understanding of GLSL, but you can experiment with provided files even without it.
In the first part I explain a bit raymarching process in general and go through different parts of GLSL algorithm. And the rest of the video is an different approaches to create and manipulate SDF geometry in Touch.
Second part is about manipulating lights and colors, including reflections, enviromental mapping and better integration of raymarching inside GLSL TOP with polygonal geometery rendered in a standart manner with a Render TOP.
And third part is about different approaches to warping a space as an instrument of modifying geometry: trigonometrical functions, gyroids, endless repetitions, kaleidoscopic iterations, fractals and so on.