I find that writing expository notes is both fun and a good way to improve my own understanding. I decided to share my notes here with the hope that someone will find them helpful, even though their primary purpose is to organize my knowledge. They are probably not good for introductions because they lack exercises, examples, and motivation, but I think they could be useful as reference material.
All these notes should be considered living documents in the sense that they will be updated irregularly and without warning as I expand and improve the existing contents, learn new things, and correct errors. Any feedback is greatly appreciated and should be directed to gwthomas@stanford.edu.