Glee-cap!
So it all starts with Caroline Fabray, a new student from a private boarding school Across the Pond, who shows up in McKinley's Halls and immediately manages to get on the bad side of Nikki Hardy, Head Cheerio and new HBIC of the school. Unfortunately for Nikki, Caroline immediately catches the eye of Coach Sue Sylvester based on her status as younger sister to infamous Quinn Fabray, along with her own proficiencies in dance and gymnastics. Sue decides to send in one of her top dogs, Nikki's best friend and former Enforcer Stassi Moran, along with Nina Grannis, Annie Hudson, and Michelle Harrison to bring Caroline into the fold by infiltrating Caroline's club of choice- Will Schuester's own New Directions.
Caroline, meanwhile, has created her own bond with fellow freshman Katie Benett, a bubbly blond with a love for Twizzlers and forensics, which unfortunately makes her an easy target for the Cheerio's attacks. Katie also finds a comrade (and later boyfriend) in Dylan Jamieson, who takes great pains to hide his father's drunken and abusive tendencies toward himself and his brothers from the rest of the world. Caroline herself finds a love interest in Artie Abrams' younger brother Teddy, a junior and future director who connects with fellow AV geeks sophomores Liam Stewart and Andrew Harold.
However, in order to look after Caroline, Stassi has taken the lead with Nina, Annie (who's begun to take a shine to blind student Hayden Bryant, and Michelle (who's older brother Everett rules the theater scene) in the civil feud that has begun between the Gleeks and Populars. She has also begun a secret relationship with resident trouble-making sophomore Hayley Montenegro, who's violent tendencies and penchant for pranks has recently placed her under the more refined tutelage of Liam. Because both girls are still publicly closeted and both are fierce public rivals, their romance is strictly limited to supply closets and empty classrooms.
Being separated from her best friend and not true friends with the "good Cheerios", Stassi finds an unlikely connection with freshman Gleek Roxie Lovely, who also catches the eye of popular baseball player and resident rich kid Dalton Johnson, whose Cheerio twin sister Jennifer fervently hates both Caroline and Stassi while idol-worshipping Nikki. Dalton happily includes Roxie (and Stassi) into his circle of friends, which includes sophomore player Walt Devlin (who's recently developed an odd friendship with Michelle), easy-going gay jock Coby Pally (who's made quite an impression on Everett), and academic Ashwin Chima, who's recent break-up with super-overachiever Emma Malley has caused him to begin dating the artsy ditz Rhi Gauthier, who is well-known for her flighty and opportunistic romantic tendencies.
Emma, meanwhile, has begun to crack under the pressure she has put upon herself, and not even wise words from curvy lesbian crusader coworker Addie Baxter or the timid friendship developing with former rival Liam can reason with the easy fix for nerves and physical insecurities that Stassi has offered, causing the perfectionist to start down a path to join the Cheerio.

For more details, check out the Glee_New_Directions:_New_Generation_Wiki (link available on my profile)!