Oooh it's my lucky day! My thesis is on the peace process, so I've accumulated a pretty big bibliography as I've gone along; I'll give you some good references to get you started below. It's a really fascinating moment in time to study. Just out of my own curiosity -- what has piqued your interest in looking at the IRA in particular in relation to the Good Friday Agreement?

Please note, in flagrant disregard of your specifications (I'm sorry!), these are all books:

Bryan, Dominic. Orange Parades: The Politics of Ritual, Tradition and Control.

• Bryan is an anthropologist, and this book marks the first anthropological study to focus solely on the Orange Order; his research ran concurrent to the peace process and so gives some insight into the Protestant community at this time.

de Bréadún, Deaglán. The Far Side of Revenge: Making Peace in Northern Ireland. 2nd edition. Cork: The Collins Press, 2008.

• de Bréadún is a veteran journalist in NI, and presents a very compelling and readable account of the process here.

Gallaher, Carolyn. After the Peace: Loyalist Paramilitaries in Post-Accord Northern Ireland. Ithaca: Cornell University Press, 2007.

• This book offers a nice counterpoint to your interest in the IRA vis-à-vis the Agreement.

Gilligan, Chris and Jonathan Tonge. Peace and War? Understanding the Peace Process in Northern Ireland. Aldershot: Ashgate, 1997.

• A nice, easy-to-understand introduction to many of the major events and elements of the peace process.

Jarman, Neal. Material Conflicts: Parades and Visual Displays in Northern Ireland. Oxford: Berg, 1997.

• Like Bryan, Jarman is an anthropologist (in fact, the two have worked together quite extensively), and this book is the result of fieldwork performed throughout the late 1980s and early 1990s, if I recall correctly; it predates the GFA itself, but is instructive in exploring the ways in which material culture and rituals (murals, images, parading, etc.) shaped the sectarian divide in Northern Ireland during this time.

McKay, Susan. Northern Protestants: An Unsettled People. Belfast: Blackstaff Press, 2000.

• I love this book. McKay is another veteran journalist, and this book chronicles her conversations and interviews with Protestants all over the state in the lead-up to the passing of the GFA. It provides a window into a great many different Protestant states of mind and opinions on the peace process and the Agreement. Part of it is available online here.

McKittrick, David and David McVea. Making Sense of the Troubles: A History of the Northern Ireland Conflict. London: Penguin, 2001.

• By a couple more journalists, this is an excellent and very accessible primer for a background of the Troubles; it's my go-to citation for such a purpose, and includes three or four chapters that directly address the peace process and cover up to about the year 2000.

McAuley, James W. and Graham Spencer. Ulster Loyalism after the Good Friday Agreement : History, Identity and Change. New York: Palgrave Macmillan, 2011.

• A nice recent collection of essays on, you guessed it, Ulster loyalism after the GFA.

McLaughlin, Greg and Stephen Baker. The Propaganda of Peace: The Role of Media and Culture in the Northern Ireland Peace Process. Bristol: Intellect, 2010.

• Media coverage of the peace process played a hugely significant role (of course) in public perceptions of and conversations around it. My university offers this as an electronic resource with full-text available online; yours might as well.

Patterson, Henry and Eric Kauffman. Unionism and Orangeism in Northern Ireland since 1945: The Decline of the Loyal Family. Manchester: Manchester University Press, 2007.

Rowan, Brian. Behind the Lines: The Story of the IRA and Loyalist Ceasefires. Belfast: Blackstaff Press, 1995.

• One chapter available online here.

It ends in 1996, but I'm a fan of Tim Pat Coogan and his contribution on the Troubles is called, well, The Troubles. I've asked about him on here before (with no response) because there's a definite hint of nationalist perspective in his writing (which is fine with me; his audience -- including myself -- is primarily interested in that point of view). He doesn't let it cloud the facts, but there's a twinge of it in there, it seems.

Interpreting Northern Ireland by John Whyte I found very helpful when studying the Troubles.