Originally Posted by Aditya 
I really wish to play this, since I am a sucker for good stories in games. But this line worries me:
I am not AT ALL familiar with the setting and have never read/seen any source material. Will this really be a huge problem? Surely, there will be in-game lore to help understand the happenings..??
Not necessary, but I do recommend you watch the TV series, if only because it's just THE BEST SERIES OF ALL TIME

Events in the game happen at the same time as things in the first season/book. There is in-game lore in the codex, but you have to find the entries in your exploration, so if you don't find one, you miss it. It's pretty cool that you get references that are part of the grand story, but your story is independent.