The last issue of Smithsonian Magazine had a fascinating article on Dwight Eisenhower in the days before D-Day. There is only an excerpt of the article up online, but most public libraries will have the full magazine for you to read from (I personally subscribe to the magazine). The article is also only an excerpt of a book by Michael Korda called Ike: An American Hero so if this is a topic you enjoy, you can find lots more on it.
What I found interesting about this article is how it talked about how the decision was made to go forth with the D-Day invasion and what helped the Allies out (the article quotes Napoleon saying that he liked lucky generals and luck was with Ike in June of 1944). The Allies had better weather radar and could tell that the weather would clear on June 6th, while the Germans, who did not, thought the bad weather would continue, meaning they were caught unprepared. The original assault was planned for June 5th, but moved back due to bad weather. This was a major decision as it meant 24 more hours for the Germans to find them and it was hard on the soldiers, who were already on the ships.
When the time for the decision about the 6th to be made, Eisenhower listened to his commanders, but it was completely his decision. In preparation on the 5th for the invasion the next day, he even wrote out what he would tell the news if the landing failed and in it he took full responsibility for the failure, "If any blame or fault attaches to the attempt it is mine alone." (55) He spent a lot of the day with VIPs, but in the afternoon went out to visit the airborne troops. The causality rate for this group was predicted to go as high as 80%, but Ike believed that an airborne strike was paramount to success. Kay Summersby remembers that Ike told her after talking with these men that, "It's very hard really to look a soldier in the eye...when you fear that you are sending him to his death." (58) An American correspondent reported seeing tears on Ike's face as the C-47s rolled down the runways.
Ike's gamble paid off and after about three hours (the demolition of underwater mines started at 6:30 AM), he had his press aide announce that landings were underway in France and the Allied countries (even Stalin) rejoiced. The airborne causalities were not even as high as expected, but did prove to be critical in success. Of the 23,000 airborne troops, about 3700 were lost (58).