Short answers, pulled from the story.
Robert Catesby led the conspiracy to blow up the House of Lords during Parliament's State Opening. He participated in the Essex Rebellion in 1601 and escaped execution after paying a fine of 4,000 marks.
A search party led by Thomas Knyvet found Guy Fawkes on the 4th of November 1605. He was taken to King James early on the 5th of November after confessing under torture at the Tower of London.
The conspirators stored twenty-six barrels of gunpowder in the undercroft beneath the House of Lords. This unused room measured approximately 77 feet long and 24 feet 4 inches wide.
Catesby and Thomas Percy died from a single lucky shot during the siege of Holbeche House on the 8th of November 1605. Their bodies were later exhumed and their heads exhibited on spikes outside the House of Lords.
An anonymous servant delivered the warning to William Parker, 4th Baron Monteagle, on the 26th of October 1605. The letter instructed him to avoid Parliament on the day of its opening due to the planned explosion.