Interested in HCI? Of course you are. So take a look at this Morgan & Claypool series edited by John M. Carroll. Each entry is a small monograph on an HCI topic. They're all blind reviewed. Currently they seem to be priced at $20 a pop, which I think is quite reasonable for these compressed, focused monographs.
Most interesting for me is the upcoming Kaptelinin and Nardi monograph, "Activity Theory: A Primer for HCI Research." I was privileged to review the manuscript. It's a great, compressed discussion of AT and how it relates to HCI - and an efficient, focused text that makes a great introduction to AT in general.