Are there any plans on the horizon for a book detailing the internals of the Mega65 hardware, such as the VHDL implementations of the C65 chips? This would be really interesting reading.
If the goal is an interesting read, then going through the blog from the beginning through all the twists, turns and adventures is a good option. If you are after current information, then the Guide that Deft shared above is the best place. Expect it to get updated in various places over the coming weeks, as I am using the MEGA65 to teach an operating systems course.
LG
Paul.