You need the NATO Handbook, the 2001 version was ISBN 92-845-0146-6...might be a new one out there, I work at NATO and that is the most recent one I have! Check the NATO web site listed above, or write the NATO Office of Information and Press at 1110 Brussels, Belgium (that's all the address you'll need) or email
[email protected]
Sorry, can't help you on the UN, I use their web site as well!
Cheers! M2