Here is another new logic book from CUP, Proof Complexity by Jan Krajíček.
This is a rather weighty (and very pricey) tome by a distinguished author in a weighty (and distinguished) series. Maybe it is not the place to start if you are new to the area! — but, dipping in, this does look full of interest if you already know some of the issues and themes.
Surely a book, then, to order for your university library. But you can judge for yourself — for the author has (at least for the moment) provided a link to a PDF of a late version of the book here. And there are related materials elsewhere on his website.