Short answers, pulled from the story.
The Coronation of Napoleon took place on the 2nd of December, 1804, at Notre-Dame de Paris. It followed the French constitutional referendum of 1804, which overwhelmingly approved Napoleon's elevation to emperor.
Napoleon crowned himself to symbolize that he was becoming emperor based on his own merits and the will of the people, not through religious consecration. Historian J. David Markham, head of the International Napoleonic Society, noted that Pope Pius VII knew about the move in advance and raised no objection.
Pope Pius VII traveled to Paris to officiate at the coronation and recited the crowning formula Coronet vos Deus. After the Mass, he retired to the Sacristy rather than preside over the civil oath, objecting to its contents.
According to government tallies, the entire cost of the Coronation of Napoleon exceeded 8.5 million francs.
The golden bees were drawn from the Merovingian tomb of Childeric I and were chosen to link Napoleon's new dynasty with the ancient Merovingians rather than the Bourbon line. The bee replaced the fleur-de-lis on imperial tapestries and garments.
Jacques-Louis David painted the coronation, producing the celebrated work titled The Coronation of Napoleon. A commemorative medal was also struck with a reverse design by Antoine-Denis Chaudet.