Short answers, pulled from the story.
Prudence Farrow locked herself inside a small bungalow for three weeks while meditating with intense seriousness in the foothills of the Himalayas. John Lennon and George Harrison were assigned by Maharishi Mahesh Yogi to coax her out of seclusion because they had experimented with LSD before discovering meditation.
John Lennon wrote Dear Prudence using a finger-picking guitar technique he learned from Donovan who followed the Beatles to Rishikesh. He mastered the fast learning process in just two days according to Donovan's recollection and detuned the sixth string down to a low D to achieve an arpeggio effect.
The Beatles recorded the song at Trident Studios in London between August 28 and 30 1968. On August 28 the three remaining Beatles completed the basic track using eight-track recording equipment instead of their usual four-track gear.
Apple Records released The Beatles double album on the 22nd of November 1968 with Dear Prudence sequenced as the second track on side one. Its introduction was cross-faded with the sounds of a jet aircraft landing that concluded the previous track Back in the U.S.S.R.
John Lennon's original handwritten lyrics contain fourteen lines and some doodles which sold at auction for US$19,500 in 1987. Rolling Stone ranked the song at number 63 on its list of The Beatles' 100 Greatest Songs in 2010 while Mojo placed it at number 44 in 2006.
English post-punk band Siouxsie and the Banshees released a cover version of the song as a single in 1983. They recorded the song at a studio in Stockholm in July 1983 completing it at Angel Recording Studios where Smith's sister Janet added a harpsichord part.