The nuts and bolts of writing, and especially of writing fantasy, are what I address here. This has nothing to do with selling one's work; that's for the Business group of essays. This is about how you produce that work in the first place.
In addition to these informal essays, I've also published five nonfiction articles with Strange Horizons, several of them based on academic papers. Their general focus is on concepts from particular cultures, which might be of interest to the fantasy writer.
I also maintain a list of links through del.icio.us, a very interesting service I recommend to others. It can be accessed through an RSS feed. Feel free to take advantage of my research efforts!