Reply #2: It's damned entertaining but I think Manchester fell way too much in love

[Two Sheds]

with his subjects (I include Douglas MacArthur). Churchill's greatest asset was that he wrote history almost at the same time he made history. It has helped his image enormously. To balance out the picture of pre-war Britain, I recommend AJP Taylor's The Origins of the Second World War. Taylor's book was controversial when it came out. He maintains that Churchill used cooked statistics about German rearmament. Also, to defuse criticism of Chamberlain from some quarters, Taylor makes it very clear that the policy of appeasement was approved by an overwhelming majority of Britons at the time. When Hitler went back on his word at Munich, Chamberlain knew that war was inevitable but he couldn't have gotten the country behind an aggressive policy before then.
Don't forget also that if not completely ready by September, 1939, England had somewhat rearmed itself under Chamberlain before Churchill was brought into his government as First Lord of the Admiralty. The most effective criticism of Churchill by Manchester comes in the second volume when he describes how Churchill destroyed an earlier movement for building England's defenses by his disastrous support of Edward VIII in the abdication crisis.
I would also recommend The Last Lion but my favorite Manchester books are The Arms of Krupp and his memoir of his war service in the Pacific, Goodbye Darkness.