The Blogosphere can be a great source of information to build your reader's advisory knowledge. Right now plenty of new books news is coming from Book Expo 2007. My favorite posts come from Bully, you can read about the expo from the point of view of a little stuffed bull - Day One and Day Two.
Elsewhere, Fuse #8 tells us all about the Random House Preview of forthcoming books.
Big A little a reviews the Meet the Authors series.
Oz and Ends reviews the Silver Sequence trilogy.
Bookshelves of Doom loves Skulduggery Pleasant.
Roger Sutton lists the latest starred reviews in the July/August issue of Horn Book Magazine.