Found a great resource on rendering fractals, written by Mikael Hvidtfeldt Christensen, who is a physicist and a software developer (and apparently an expert on fractals rendering.)
He wrote a 7-part (so far) article on rendering fractals. His series is almost a one-stop resource for all things related to rendering fractals, covering topics from coloring and lighting, to complex math associated with generating different types of fractals, such as Julia sets and Mandelbulbs.
Most of the rendering part I have already figured out from various other sources, but it is a great read nonetheless, and has given me a few more ideas on various rendering passes. The part that is most useful is the part on modeling and generating fractals. This opened up a whole new area that I am completely new to. There is a tremendous amount of math involved, and it is a rather difficult read. A lot of the math I do not understand, and I am still working on the reading and figuring it out.
I only wished I had found this blog earlier!
Here are some amazing images from stuff he's working on. This guy's a true expert!