The Marvel Way is a great place to start to get your basic fundamentals down. You have to get those fundamentals or your work is going to look flat, misproportioned and just ugly, no matter how good your polish is...
next, don't look at your comic books. You will get depressed. I look at a Kirby comic and want to be Kirby so bad, but if I keep looking at Kirby I will just be a bad rehash of Kirby. If you are interested in comic book style art, well, wait until you get those fundamentals before looking at your favorite artists, that way you can break down the work in your head, seperate style from mistakes and get a really good feeling for what it is that makes the art work, not what makes it look cool.
Perspective books are essential, as are anatomy books. Grey's anatomy is a must have for EVERY body who wants to draw the human form.
I will tell you, very stern faced... avoid, I mean AVOID Burne Hogarth's anatomy book. Hogarth is a great artist but if you use the techniques he presents in his books in toto then your figures will look like Hogarth figures or somewhat dumpy and fat. His books on Hands, Drapery and Figure Drawing (not the Anatomy book, they are different) are good... especially the drapery book if you are having problems in that department.
Andy Smith's book IS VERY MUCH a good book, on par with the Marvel book, as is Chris Hart's Drawing Superheroes and Villains, couple it with Drawinbg Cutting Edge Comics and you have some decent resource material. Cutting Edge really helps in jazzing up your female figures without looking like John Byrne drew them.
One thing I do now that I have been drawing and have a good understanding of drawing comic book style work is looking at sketchbooks, especially the ones that show pencils and the blue line pencils as well. You can really learn a lot by seeing the skeletons of other people's work.
Joe Kubert has a great book, Superheroes... buy it.
Two must haves for comic book art... Comics & Sequential Art by WIll Eisner and Scott McCloud's Guide to Understanding Comics.
Jason