I really think it's bad not to read the books if you're a main actor in its television series, especially since it's supposed to be a somewhat faithful adaptation of the books. And Cersei is Cersei, she's crazy in books 1-5.
Please folks - understand one very elementary, basic point. The actor's job is to deliver ON THE SCRIPT, not what he / she thinks "might" or "should" have happened, or what they think the original author may have written or intended. The actors cannot be second or third guessing the writers and producers. That is why so many of the actors do not read the books until after they have read the scripts, and some (like Charles Dance) do not read the books at all.
Charles Dance explains it very well in his interview, linked to via this site. He says that in the case of the writing for this show, he didn't need to go and plough through the books, because he wasn't faced with the task any actor dreads - a terrible script and trying to make a silk purse out of a pig's ear (his words). Seeing his stellar performance as Tywin, does anyone really think he could have somehow "improved" it by reading the books? I doubt it! Other actors have explained their job in similar terms - that they have to understand what they have to deliver via the scripts, and thus the books are there to provide further background or fill out any further details. And a few actors have said they have read all the books.
There is no right or wrong way to approach the task of acting: if Michelle or Lena are delivering on the characters as written in the scripts, then they are doing their jobs. And they are clearly doing them extremely well.
Edited by Currawong, 17 May 2012 - 01:23 AM.