I recommended reading Prof. Dan Joyner's book on "Interpreting the Nuclear Non-Proliferation Treaty" in the past, but it has now been published in paperback form, bringing the cost down from about $89 to about $33. The book is significant because in addition to explaining many of the legalities of the NPT which are not mentioned by the mainstream press, he takes pains to debunk some of the legal falsehoods that apply directly to the current debate about Iran's nuclear program.
Right now, I am finishing off Amb. Mousavian's memoir entitled The Iranian Nuclear Crisis. I'm making my reading list for 2013 too. I have pre-ordered the Leveretts' book, "Going to Tehran" and I am also looking forward to Gareth Porter's book on Iran's nuclear program entitled "Manufactured Crisis."