Short answers, pulled from the story.
Sir Rowland Hill proposed the radical change to the postal system on the 13th of February 1837. The government subsequently gave him a two-year contract to run this new system.
Henry Corbould provided the sketch based on William Wyon's 1834 cameo-like head, and Charles Heath engraved the final portrait. This design remained on British stamps until Queen Victoria died in 1901.
The total print run reached 286,700 sheets containing 68,808,000 stamps. These stamps were printed in imperforate sheets to be carefully cut with scissors for sale.
A red cancellation was difficult to see on the black design of the stamp, allowing people to re-use cancelled stamps easily. In February 1841, the treasury switched to the Penny Red and began using black ink for cancellations instead.
An original printing press for the Penny Black sits on display at the British Library in London today. A complete sheet without check letters held by the British Postal Museum is a plate proof rather than an imprimatur sheet.