There aren't too many good overviews of the Iran-Iraq War from what I've come across. There is, however, a book that was just released that seems to be getting some good reviews: Williamson Murray's and Kevin Wood's The Iran-Iraq War: A Military and Strategic History.

Another good book is an edited work of essays: The Iran-Iraq War: New International Perspectives, edited by Nigel Ashton and Bryan Gibson. This book is fairly expensive, though.

Lastly, Ray Takeyh's Guardians of the Revolution: Iran and the World in the Age of the Ayatollahs has a good chapter on the Iran-Iraq War within the broader context of post-revolution Iranian foreign policy.