- shane dies a whole lot quicker
- dale dies a whole lot later (and in a very different, far more badass manner - i think that character got cheated on the show)
- there is no t-dogg (or 99% of the original group - andrea, amy, rick, dale, carl, shane, lori, carol and sophia are the only book characters at the outset. most of the other characters they have since encountered are from the books or pastiches of several characters from the books).
- there is no daryl (or merle - though i believe daryl is destined to make his debut in the comics soon, if he hasn't already)
- andrea is not yet dead
- sophia is not yet dead
- carol is long dead, and not at all from being sent from the group or anything like that; she kills herself at the prison by freely walking up to a biter the group had chained up in the courtyard for research. in fact, of all the show-book characters, carol probably is the most differently characterised.
- tyreese is decapitated by the governor in the comics, not herschel; herschel does die during the prison attack, but he is gunned down in cold blood (still by the governor), after witnessing his last living son get killed in the fight.
- tyreese also has an incredibly badass moment where he gets stuck in the prison gym with an outrageous number of zombies and the others fear he is dead but go back to save him eventually and he's just sitting there holding his hammer surrounded by dead zombies, which i don't think we're going to get, sadly
- lori does not die during pregnancy, but is rather killed during the governor's attack on the prison, shot from behind through the abdomen (while carrying judith, who also dies) with a shotgun
- just a buttload of kids are there that aren't in the show, and probably with good reason: there are these twin boys, one of whom is evil (naturally), two girls that get decapitated in the prison by an insane prisoner (who was also absent from the show), tyreese's daughter and her loony boyfriend, children fucking everywhere. which i guess they started to mitigate on the show with the new additions of late.
- the governor cuts off rick's hand (which is a fairly major plot/character development thing for rick, so idk if they're gonna end up doing that later or not)
- andrea never lived in woodbury as the governor's ensorcelled offsider