Harry was born to James and Lily Potter (née Evans) on July 31, 1980. They lived in the village of Godric's Hollow under the Fidelius Charm, hiding from Voldemort due to a prophecy that implied Harry. As part of the charm, they had a Secret-Keeper, who was originally going to be Sirius Black, but was changed to Peter Pettigrew.
Peter, however, betrayed the Potters before faking his own death and framing Sirius for both. The betrayal led Voldemort to the Potters', and he killed James and Lily before attempting (and failing) to kill Harry on October 31, 1981. Lily's sacrifice has protected Harry since.
Harry was moved from the destroyed house in Godric's Hollow to 4 Privet Drive to live with his relatives, the Dursleys. He was mistreated here but was never in any serious danger (puns partly intended). His memories of his time here are few.
Harry has black, messy hair and bright green eyes, and is (very) often described as looking like his father but with his mother's eyes. He is quite nearsighted and wears black, round-framed glasses to correct this. He is fairly tall and well-muscled due to Quidditch and the physical training he has undergone through most of his life. He has the famous lightning-bolt scar on his forehead, the visible sign of the Killing Curse that didn't, and (since the end of his fourth year) a small scar on the inside of his left elbow where Wormtail cut him to provide blood for Voldemort's resurrection.
Harry's Animagus form is a dark-furred wolf, with markings on his face which resemble his glasses and scar. As a blood Heir of Gryffindor, he also has wandless control over fire, but his powers were mostly blocked off until he underwent a blood-bonding with Remus before his fifth year, allowing Remus to unblock him (as James would probably have done, had he lived). This bond, centered in an amulet which Harry wears along with his Pack-pendants, keeps Harry's mind safe from Voldemort but also means he has a form of the Muggle disease lupus.
Harry has recently been learning Occlumency from Severus Snape, in case his blood-bond with Remus should fail (as happened once already, when Remus was badly injured in a Death Eater attack on Diagon Alley). He is also capable of astral travel, or out-of-body work, and has trained himself to fall asleep on cue to facilitate this ability.
Harry's wand is holly and phoenix feather (the feather is from Dumbledore's friend Fawkes), and eleven inches long exactly. He has some talent for wanded magic, being the second of the Pride to complete his Animagus work, and has begun to enjoy Potions more since Professor Aletha Black took over from Severus Snape.
As with all the Pack's cubs, Harry reads music and plays the piano passably, though he prefers singing to instrumental work. He also enjoys cooking, and acts as Danger's usual kitchen help for holidays or her replacement when she is ill. From watching Remus and Dumbledore most of his life, he has learned how to lead people without the people necessarily realizing it.