I wish to create shaders for Unity, but I know almost nothing on the subject. Where can I go to find some documentation on the matter?
You will find a lot of info in official Unity Manual
It’s a good idea to analyze the code of standard shaders available in Unity, as well as custom shaders available for example at Unity Wiki.
I also suggest reading through NVIDIA Cg Tutorial. It’s a comprehensive step by step guide, containing a lot of useful information and examples.