As others have pointed out, I think "self-taught" is a bit of an oxymoron. You can't teach yourself what you don't know, but you can learn from others in a variety of ways. I've had a small amount of formal training: In high school, I took the one photography class available back in the late 80s. Most of my early work wasn't very good but I enjoyed shooting, and I especially enjoyed working in the dark room. I used to stay after school whenever I could, and spent a lot of time splashing around in chemicals.

A few years ago I took a night class at the local university titled "Advanced Photoshop". The instructor was knowledgeable and helpful, and I learned a lot in that class. In particular, I learned how to use layers, which has been enormously helpful. I still go back and periodically review the audio recordings I made. Learning PS is a lot like learning a language: if you don't practice it regularly it's easily forgotten.

Apart from those two formal bits of training, I've learned from the Web (Youtube has been especially useful), as well as books by Scott Kelby and others. And of course I've learned a good deal by taking many crappy photos.