Since most of the characters exist already, I was thinking we could claim preexisting characters. The year is going to be 1976-1977, so I will list their ages. :) Here's a list of them.
Adrian Ambrose (16): Hufflepuff- Member of the Slug Club, grew up to be a photographer~ You
Bertram Aubrey (17): Ravenclaw- Had an illegal hex used upon him by James and Sirius~Me
Edward Avery (17): Slytherin- supported Lord Voldemort ~ You
Sirius Black (17):Gryffindor- You know all about him I'm not listing anything else.~Me
Regulus Black (15): Slytherin- Younger brother of Sirius , Chaser on the Quidditch team~You
Dirk Cresswell (15): Hufflepuff- Member of the Slug Club, became head of the Goblin Liason Office.~You
Bartemius Crouch Jr. (14): Slytherin- Son of Barty Crouch
Lily Evans (16): Gryffindor - You know all about her I'm not listing anything else.~ Me
Davey Gudgeon (16): Hufflepuff- was injured by the Whomping Willow~You
Alice Lightwood (17): Gryffindor- Eventually joined the Order and married Frank Longbottom, was tortured to insanity by Death Eaters. ~ Me
Remus Lupin (16): Gryffindor- You know all about him I'm not listing anything else. ~ Me
Mary MacDonald (16): Gryffindor -Was hexed by Mulciber because she was a Muggle Born, friends with Lily Evans ~ You
Marlene McKinnon: Gryffindor- eventually joined Order, Lily Evan's best friend ~ You
Frederick Mulciber (17): Slytherin- hexed Mary MacDonald~Me
Peter Pettigrew (16): Gryffindor- You know all about him I'm not listing anything else.~You
James Potter (16): Gryffindor- You know all about him I'm not listing anything else.~ You
Evan Rosier (17): Slytherin- Was a death eater later in life~ Me
Severus Snape (16): Slytherin- You know all about him I'm not listing anything else.
Andrew Stebbins (16): Ravenclaw- was admonished by Flitwick because he would not put down his quill after an exam ~Me
Lucinda Talkalot (16): Slytherin- Slytherin Quidditch Captain~Me
As more come up, we can claim them. We can each take turns picking who we want. ;) You first!