There are lots of books i have read on the Great war. I have read a few of the above mentioned but if you want two sides of the coin so to speak then read these two.
Mud , blood and poppycock which i know has been mentioned which IMO states that there was not alot more that could have been done that was not done and some myths where rubbish!
On the flip side of the coin there a book called "Haigs suspect command a reassessment".
This by far is my favourite as the author a man called Winter went to far colonies such as Canada and Australia to gather evidence that had been hidden from the British Archives.
It showed that many Battles where complete "Cock ups" but hidden from the public and documents destroyed, but copies had not been in these colonies.
Haig had only risen through the ranks because he mixed in high circles and was the son of the great Whisky manufacturer his record before the war was disasterous and was no where near fit enough or no enough to command an army, he lied through his back teeth , without spoiling it to much incase you decide to read it, in one push he claimed a victory for the allies by saying we had killed 600,000 germans when he knew it was just 300,000.
And said we had gained a mile into there terrotory when infact we had gained 40yards!!!!!!!!!!!!!!
I know propaganda in war is not un-common but he made "gerbils" look like an honest man in comparism.
He got men slaughtered and said we had lossed or won the battle on the amount of men we had killed or lossed.
Second in Command was a man called Plummer who was by far a better tactician and the men respected him, he did not and refused to in many occasions to send his men into a "Turkey Shoot" for the germans and they both fell out on many occasions.
You can make your mind up about Haig but i have read many books for and against and i think he was incompetent and slaughtered many men needlessly especially towards the end when he knew the americans had joined so he just used them like cannon fodder as he knew he had superior numbers.
Great book , you make your own mind up but i think he was "probably" the worst general that we ever had in history and many men paid for that.
And that is also a view of many historians too although they would not go as far as to say offcoarse-God Forbid!!