This may be slightly outside the scope of this subreddit, but I've recently been reading several of Antony Beevor's second world war books, including Stalingrad, Berlin: The downfall and The Second World War, and was just wondering how credible a historian Beevor is considered to be?
His Battle for Spain is quite excellent, especially on the military matters of the war. I highly recommend it along with Hugh Thomas' and Paul Preston's one volume histories of the war.
He's the boss-man.
In terms of popular military history he's one of the best out there. Obviously no history is perfect and there are flaws with everything but there's nothing wrong with him at all. I think he's quite excellent and I enjoy his very visceral style. Sometimes you need something more dry and academic but Beevor will set you up nicely with all those topics.
Just Stalingrad alone has won, "The first Samuel Johnson Prize, the Wolfson History Prize and the Hawthornden Prize for Literature in 1999."
The Russians have taken issue with his documenting the Red Army's habit of rape in Berlin.