Short answers, pulled from the story.
Stan Lee and artist Steve Ditko are credited as the co-creators of Spider-Man, with the character first appearing in Amazing Fantasy #15 in 1962. Jack Kirby and Joe Simon also contributed early ideas that fed into the concept, but Ditko redesigned the character almost entirely, and Lee himself said Ditko deserves co-creator credit.
Publisher Martin Goodman gave Stan Lee what Lee called "1,000 reasons" the character would fail: nobody likes spiders, the name sounded too much like Superman, and a teenager as a superhero seemed implausible. Goodman only allowed the tryout because Amazing Fantasy was already being canceled.
The death of Gwen Stacy in The Amazing Spider-Man #121, cover-dated June 1973, is considered a turning point for the entire superhero genre. Historians argue it helped end the idealistic Silver Age of Comics and usher in the darker Bronze Age.
In issues #96-98, Marvel published a three-part anti-drug story arc without the Comics Code Authority's approval because the Code banned any depiction of drug use. The issues sold extremely well, and the Code was subsequently revised to allow such content.
In 2014, global retail sales of Spider-Man licensed products reached approximately $1.3 billion, exceeding the combined global licensing revenue of Batman, Superman, and the Avengers. From 1966 to 2012, The Amazing Spider-Man sold an estimated 145 to 150 million copies.
Spider-Man acquired an alien black costume during the Secret Wars miniseries in the mid-1980s. He rejected it after discovering it was a living symbiote. The symbiote then bonded with Eddie Brock, a reporter who despised Spider-Man, creating Venom. Because the symbiote had bonded with Spider-Man first, Venom is immune to Spider-Man's spider-sense.