I've watched every episode and I have no idea who Roose Bolton is. :/
His house is much better set up in the books, as is the Frey house. The show replaced his establishment in Clash of Kings with Arya serving Tywin.
Oh, yes, It was Tywin on the TV series. I keep mixing the books up with what is on TV. Can you remember when Roose Bolton first appeared in the TV series?
I do remember that at one point in the TV series one of the characters, can't remember who, mentioned that the flayed man is Bolton's sigil.