We know very little about the Others. Most of what we do know is told to us door people who never saw them but heard plenty of stories that have been circulating from the last time they were seen, some measly 8,000 years ago.
As I remarked earlier this season, Game of Thrones is moving along at a pretty rapid clip. After taking four years to get through three books, it very much seems like the toon will get through two enormous boeken in practically one season.