I bought the book "Blackhawk Down" before I bought the movie. It was a real eye opener. He had all access to interview the rangers, the command staff, and incredibly, the Delta members, and Gary Gordon's and Randy Shughuart's wives.
One part that sticks in my head, at the time President Clinton went to visit the wounded rangers in Germany, and let them know they did a good job and the rest of the unit would be home. One of the rangers cursed him out, saying that we should go back in, not hide with their tails between their legs.