A fun list from The Millions that will be your TimeSuck of the Day. Off the top of my head, some notable omissions:
Lazy Book Reviews (moved away from the original mission, but Nicole is very funny and a pleasure to read)
The Bat Segundo Show (a supplementary Tumblr that highlights archival material)
Bookrageous (picks, highlights, and more from the bookish podcast)
I suspect this list will only get bigger as the day goes on.