There was no way they could to a accurate adaptation of the books. Too many characters, too many storylines, so they had to make decisions, small ones at first, that have bigger impact as the story goes on.
George RR Martin posted on his blog about it (
http://grrm.livejournal.com/427713.html ), have a look.
So, the absence of some characters make them 'adapt', and it escalates as stuff goes on. No Jeyne Pool? Marry Sansa, and also kill Mance since he doesn't have to go save her! Jaime doesn't take the Riverlands? Send him to Dorne! Bla bla bla.
So, just take it as it is. Two different tellings of the same story... one complete and original, the other a often weak adaptation, but
"And yes, more and more, they differ. Two roads diverging in the dark of the woods, I suppose… but all of us are still intending that
at the end we will arrive at the same place."
That being said, some aspects of the TV Show are just horrendous. The Dorne and Sand Snakes storyline was just appaling, seriously, seemed like a parody of itself, more like an episode of Xena the Warrior Princess... it really bothered me, but hey, screw it.
I'll keep watching though, and i'm pretty sure you will too.
Oh, forgot to add, i don't understand how Sansa's "rape" (which i disagree it was one) affects people so much. We've had physical torture - repeatedly -, heads smashed in, executions, maims, people burn in the stake, and multiple other shocking things... but its a absolute low tone, MILD (considering he usually lets the dogs RAVAGE his other girls, RAVAGE... ) scene like that which bothers people? Get a clue... that's just absurd. It really is. Theon gets his junk cut off, but its Sansa having to consumate her wedding night (which she ACCEPTED TO) that bothers people... Oh, not the multiple stabs on the belly of a pregnant woman in the Red Wedding... Absurd.