I have been subscribing to Go! magazine for some months - it is excellent IMHO.
Go! ran a series of very good articles on all of the camps in KNP and then did the same thing for other SANParks. The Kruger special edition is a collation of those articles - plus.
Go! also has an excellent website and for information on KNP go to [url=http://www.gomag.co.za/kruger/index.html[url]
There is information about all of the camps with many photographs, recommended routes - in fact all of the information that one would need for travelling to and through KNP.
Incidentally, Getaway also published a guide to KNP (first published 2005). It too is full of useful information and photos (224 pages)
The best KNP "reference" that I have ever come across is the book written by Wilf Nussey with photos by David Paynter. It was first published in 1986 and the content is still relevant today - not much has changed in KNP in terms of camps and roads. It is still a great book to dip into before, and after, a trip to KNP, I reckon.
If you do not have a copy, I strongly suggest that you look in all of the second hand bookshops that you can find!