The three most important writing lessons I’ve embraced and actually utilized in my work are the following:
Jim Butcher’s livejournal blog.
An amazing resource, every post is just a lesson in itself to understand storytelling. The irony is that I also bought his mentioned teacher’s book, the Formula something, but that didn’t help me at all. The way Jim distills it is perfect for me and I use it all the time.
Save the Cat
It’s about screenwriting but I found it immensely helpful in creating the concepts and the needed neural pathways in my brain to comprehend and develop storytelling. I believe that the way to truly understand something is to learn the vocabulary and learn to notice the patterns in it, and Save the Cat does just that.
I’ve extended the beat sheet with the notes from the second book.
I’ve written everything with the use of the beat sheet, and at some point I found myself jotting down less and less until someday I didn’t even need one to write a short story, it all just fell into place.
Brandon Sanderson’s Creative Writing Class
These classes are like going to writing university, in essence. He explains so much stuff in such a wonderful way, it’s worth studying these videos again and again.
Bonus! Writing into the Dark.
By Dean Wesley Smith, very good for advanced authors. Find it here