Came across this whilst browsing a couple of days ago:
It's a really valuable site with orginal documents, links to some great video footage and documentaries and lots of other good source material.
It comes with a health warning however. There's plenty of material on the web that is partisan and this site is no exception - it's sympathies are right wing and anti communist. That said, the links to BBC documentaries, National Security Council minutes and Cuban Government papers mean the reader can ignore the commentary and go straight to the original material. And it's great to have the links in one handy place.
Another handy site is http://www.warinangola.com/ - it's stuffed with a wealth of information. Sadly, the bias of the publishers is strongly pro South Africa/UNITA. Reading some of the commentary is creepy, it reminds me of those interviews and books written by Nazi generals who rewrote the history of the war on the Eastern Front but couldn't avoid the glaring fact they lost.
That said there is much on both these sites that we can use for The War for Slow Readers as the events of 1975-89 unfold in our alternative history.