1) Finding Your Religion by Scotty McLennan
It sounds like a 'Faith for Dummies' type deal, but it is a really deep look into a very ecumenical view of religion. Even if you aren't "religious" in the traditional sense, I think this book would be excellent. It might give you a better idea of the ins and outs of organized God-seekers. He breaks down spiritual maturity into 9 stages, which have flaws, but for the most part have merit.
Buy it
2) Listening Hearts: Discerning Call in Community
This one is for someone who considers her/himself to be religious or spiritual, and for someone who is looking for vocational direction, or direction in anything. It is the book that my discernment committee is working through. I've read the whole thing twice and I am going through it at a pace with the rest of the committee now. I keep finding more wisdom and I'm running out of margin space and post-it tabs.
Buy it