Decided to keep going with the research rather than trust my frazzled brain to know the subject. That said, I fairly zoomed through books on the second, more familiar mythology. This was essentially review, refreshing, compiling a checklist of sorts, and I still ended up with about six pages of scribbled notes to key into my world guide.
Of the mega stack, seven books turned out to be especially helpful, and I'm keeping them under my nightstand so that the knowledge can sink into my mind as I'm sleeping (call it "wishful thinking"). I also poked around a little online and found a site with fantastic photographs for setting reference.
Tomorrow I'll organize it all and move onto character building--protagonists first.