Timeline

Turning Points
Pearl Harbor
Pearl Harbor was an attack on the U.S. military base on Oahu by Japan. The attack began at 7:55 AM on Sunday, December 7th, 1945. Relations had already been getting stagnant between the U.S. and Japan. Japan's increasing aggression wasn't something the U.S. liked, so they began to discontinue communications. Japan's attack didn't just decimate the base and kill many Americans, it ended America's neutrality.
America, although neutral, was helping out the allied forces. When Japan, an axis power, attacked, America entered the war. This drastically affected the war, since now America, always a heavy-hitter in wars, was on the allied side. Now America wasn't just supplying the allied forces, they were fighting alongside them.
Primary source: Newton Brook's Remembrance of the Helm's Ordeal
This is one soldier's account who was aboard a ship as the Japanese attacked. He briefly describes what happened while he was there.
Pearl_Harbor_Map.jpg
This shows which ships were damaged.
pearl-harbor-attack.jpg
This is a picture of a ship exploding.
Stalingrad
Germany attacked the Soviets in Stalingrad, and the fighting went on for many months, until it ended in February 2nd 1943. The Russian (soviets) army fought Germany from inside, and forced the Germans into an intense, urban-war situation. A massive force of three Russian armies attacked from the outside, trapping the German army inside. The next day, two more soviet armies attacked, effectively crushing the German invasion.
This defeat hit the Germans hard. It threw Hitler's offensive in the Soviet Union into total disarray. Aside from that, the really important part was the actual battle. It was one of the bloodiest in history, with the Soviets losing an estimated 500,000 men and the Germans losing about 300,000. Civilian casualties are thought to be even higher. This is often thought to be the main turning point in WWII.
Primary Source: Survivors of Stalingrad
This is a Youtube video of part of a movie called Survivors of Stalingrad. This video shows many images, and has some captions of speech from the survivors. One quote said that they were unable to bury anymore dead soldiers, and that they had been piled up liked chopped wood.
stalingrad-map-counterattack.png
This map depicts the German front as the Russians made their counterattack.
stalingrad-1.jpg
This shows soldiers near a house that has been destroyed, probably from shelling.
The Atomic Bombs
The bombs dropped on Hiroshima and Nagasaki pretty much ended the war, as Japan surrendered. Tens of thousands died in both cities, and large parts of the cities were leveled. Not only did many Japanese die from the initial blast, even more died radiation-related deaths, possibly years later.
This was important because it was the end of the war. Not only that, it was the first and only time nuclear weapons have ever been used. Seeing the damage caused by these weapons inspired many other countries to want build their own weapons, which eventually lead to an arms race. After Japan surrendered, U.S. soldiers occupied the two bombed cities, which of course caused political repercussions.
Primary Source: Survivor of the Bombs
This is an interview with a woman who was just a schoolgirl at the time of the atomic bomb.
Hiroshima.jpg
This is both a map and a picture, as it is a screenclipping of two pictures together. It is from the Wikipedia article on the atomic bombs. The left picture depicts Hiroshima before the bomb, and the right picture depicts Hiroshima afterward.
Bibliography
Picture Bibliography (from top to bottom)