Understanding Comics: The Invisible Art
The DC Comics Guide to Writing Comics
Words for Pictures: The Art and Business of Writing Comics and Graphic Novels
The War of Art: Break Through the Blocks and Win Your Inner Creative Battles
Great, great list. Here are a few I’d suggest too:
Good Advice on Writing by William Safire + Leonard Safir
Double Feature: Hitchcock Truffaut + Eisner Miller
Dan O’Bannon’s Guide to Screenplay Structure (great for story in general, whether you’re writing screenplays or not)