I'm a fan of zombie movies but not much of a comic book enthusiast. I've read most of the Walking Dead comic scans uploaded here by DrunkandNaked (thanks for uploading them, mate) to learn how different the stories are. You'd be surprised at how different the plot is.
The basic thing about the show is it got the rights to the name and uses the characters from the comic book. Most of the characters from the comic book got borrowed for the show, but they were made more plausible for the audience. A lot of things differ in the main story - like Sophia never dies in the comic book. There's no Darryl (!) in the comic book, either. Basically, if there's no Darryl, you could conclude with "the comic book is pure shit." Yep, it is. It's diarrhea. Rick is a typical douche bag tough guy and boring. Unlike the Rick from the show who's deeply touched by what happens and emotional
Rick's wife isn't ugly and annoying in the comic book and his son's not a retarded brat causing trouble. The comic book is fucking boring. Some characters get killed by the zombies, but that's it. There's no dramatic twists like when that Mexican left Otis for the undead to get away. Or when Rick killed the Mexican (the kid kills him in the comic book). Or where the Mexican is a stinky piece of shit (it's not highlighted enough in the comic book).
There's a lot of other stupid stuff in the comic book. Like a black girl wielding a katana (WTF? What kind of a geek is the author?) or the kid getting half of his face blown off and surviving that. Most importantly, there's no Darryl in the comic book.