What counts as spoilers? Anything new about the characters or what happens. "I like the part where X deals with Y--" is a spoiler. "I like X's character development" (without specifying what that development is) is not a spoiler.
Announcements of arrivals are always welcome--I (and my agent) like to know when books become available in different places. I'm particularly interested in books found at Borders stores, in light of stores closing and open stores reportedly having fewer books.