The wikis are still useful if you've read the books, unless you've read them all a dozen times like most of the wiki editors have. Even the conversations on this thread, which are, I would imagine, significantly less obscure than the conversations that the real experts have, often require me to consult the wiki to remind myself who some of these characters are. I'm re reading the series right now and noticing a lot that I missed the first time. For starters, I remember the Blackfish being a much more minor character than he was. He doesn't actually appear that many times, but people spend a lot of time talking about him.
One thing that the books have and is missing from the show, I think, is the idea of how big and how old this world is. Every name has a story and a character trait and every family has a history that goes back hundreds, if not thousands of years.