The other books in the series are, in chronological order:
I discovered these books years ago and really love them. I cannot wait to read Seer of Sevenwaters.
EDIT: I wanted to add that there's a creative writing competition (you can find the info here) to win a signed copy of Seer of Sevenwaters when it comes out. I'm pretty excited, and am trying to come up with something good to submit. Wish me luck! :)