Korean War by Max Hastings
Written in the mid eighties, Max Hastings was able to draw upon interviews from veterans of the war including Chinese veterans. Given that the book covers the whole of the Korean War it can not cover the opening stage of the Korean War in great detail but if you wish to gain a good overview of the Korean War as a whole, then as usual Max Hastings as in his many other books on military history tells the story well.
It is published by Pan books. The ISBN number is 9780671528232