I'll try my best.
In the comic universe of Spidey, there was a huge off-planet event called the Secret Wars. One of the major developments out of this was the introduction of a symbiote that attached itself to Peter Parker, causing a huge increase in his powers. This led to a black Suit, which was the symbiote Venom.
Quote from Wiki page:
As Spider-Man touched the black blob, it flowed over his body, forming a new costume which he soon discovered responded to his thoughts, was able to mimic street clothes and seemed to provide an inexhaustible supply of webbing. Once back on Earth, Spider-Man learned the true nature of the costume, and discovered that the symbiote desired to fuse permanently with him, enveloping him at night as he slept, using his unconscious body to go out and fight crime.
Strength was increased, the suit was able to change shape according to the hosts needs, and Spidey was indeed a happy superhero. If memory serves me correct, Reed Richards then informed Spidey that the suit was alive and possibly intelligent. The end result is that the suit tried to control spidey, but was removed - I don't want to say how in case it spoils the movie plot.
I have a funny feeling however that they may use the Ultimate Spider-Man origin of Venom, which was a biological suit developed by Peter's father, which was designed to boost the bodys immune system and help fight off cancerous cells. However the suit has a low level of intelligence, which again increased angry and hostile feelings to the host. Another difference is that the suit actually fed on the host if there was nothing in the vicinity to feed on.
Link to Wikipedia info -
http://en.wikipedia.org/wiki/Venom_(Marvel_Comics)
