Short answers, pulled from the story.
Faramir received a prophetic dream in the year 3018 that mentioned a broken sword and the awakening of Isildur's Bane. This vision haunted him while he commanded the defense of Osgiliath against Sauron's forces.
Faramir met Frodo Baggins in Ithilien after wading down to the Anduin river where he found the dead body of his brother Boromir. Orcs had killed Boromir after Frodo left the group, and Faramir questioned Frodo about his quest while hiding this knowledge.
Tolkien admitted in a letter that Faramir was the character most like him because both men were soldiers and scholars who revered old histories. Tolkien served as an officer in the British Army during the First World War and fought in the Battle of the Somme in 1916.
Christopher Tolkien recorded that his father did not foresee Faramir's emergence during early writing and invented the character only at the point where he appears in The Two Towers. This late introduction led to postponement of the book's dénouement and required further development of background for Gondor and Rohan.
Andrew Seear voiced Faramir in the BBC's 1981 radio adaptation while David Wenham played him in Jackson's film trilogy. Wenham joked that he got the role because both he and Sean Bean had large noses, though the film introduced deviations from the text regarding Gollum.