USA Today also provides some info on our heroes, and reveal a little about where we find them at the beginning of the movie. There's more at the link below too.
"The movie teams five disparate personalities: Peter Quill (Pratt), aka Star-Lord, was taken from Earth as a 9-year-old, possesses a mysterious orb artifact and pilots the Milano, a muscle car of a spaceship. Gamora (Zoe Saldana) is connected to Thanos, arguably the cosmos’ biggest baddie. Drax the Destroyer (Dave Bautista) is a muscular dude you don’t want to upset. And then there are the aliens Rocket Raccoon and Groot (computer-generated characters voiced by Bradley Cooper andVin Diesel, respectively), who are best pals and potentially the biggest things to happen to pop culture since Chewbacca.
Their stories converge in the space prison Kyln. After the characters break out, they venture to Knowhere (the severed head of a celestial being that serves as a hangout for aliens) and visit the weird menagerie of the Collector (Benicio Del Toro). They also have to avoid two villains, Ronan (Lee Pace) and Nebula (Karen Gillan), who are in hot pursuit of Quill’s orb, which has the power to destroy the galaxy."