Last Friday Russian citizens celebrated the Stalingrad victory by marching in Moscow, St Petersburg, and many other cities including Stalingrad itself (now Volgograd). I'm not up to describing that five-month battle. We danced around it here back in January 2017: http://milpubblog.blogspot.com/2017/01/old-pics.html#comment-form.
And there are scores if not hundreds of books, articles and websites describing the action better than I ever could. A great website for that time in history is at: http://facingstalingrad.com/.
It provides not only a snapshot of the battle with fairly good maps, but also interviews with a dozen German and Russian survivors. If you do not read all of the interviews, at least read that of Gerhard Hindenlang and that of the Faustova/Voronov married couple. Hindenlang was a regimental adjutant in the 71st Infantry Division. He had set up regimental HQ in the basement of the Red Department Store, where in the last days of battle they were joined by General Paulus and his 6th Army staff of 120 when they had to evacuate southern Stalingrad. Maria Georgievna Faustova was a 20-year-old radio operator with the 131st Rifle Division. Aleksandr Filippovich Voronov was a 22-year-old commander of an anti-tank battery. Both sustained wounds there. Another good read is Deutsch Welle’s English language website:
There was almost complete surprise even though the NVA telegraphed their move and there were many indications and warnings. Westmoreland is said to have been informed that attacks "may" be coming, but if he knew of the scope he did not communicate it well to his subordinates and his superiors in Washington. And reportedly there was major turf battles going on between General Westmoreland's MACV intel staff and the CIA regarding the number of personnel available to the NVA and the VC. The evening of the attack, 200 MACV intelligence staff officers were at a pool party. James Meecham, a MACV CIC analyst was at that party and said later: "I had no conception Tet was coming, absolutely zero ... Of the 200-odd officers present, not one I talked to knew Tet was coming, without exception." Westmoreland seemed to be convinced that attacks were a diversion and the real target was Khe Sanh. Actually it was the other way around, Westy was snookered by Generals Giáp and Thái.