Bart lives up to his superhero name, acting impulsively, and thinking with a brand of logic all his own. In Young Justice, he usually falls into the role of comic relief, but recent dramatic events have found him slowly maturing.
Kon-El a.k.a. Superboy... is a clone of Superman, bred after the demise of big blue. Kon was hatched, so to speak, at age sixteen with need-to-know knowledge implanted into his head. Although sharing some of Superman's D.N.A. Kon doesn't share his powers. Rather, he can immitate most with his own power: tactile telekensis (ttk). After, Kon went to work for Cadmus and was located in Hawaii, where he made his own mark.
For a long time, Kon was unable to age, living as a perpetual teen, but that has recently changed. In Young Justice, Kon is one of the team's powerhouses but also can challenge the group leader, Robin. Recently, Kon has overcome depression and with the demise of Cadmus, has started out on his own.
Cassandra Sandsmark a.k.a. Wonder Girl... got her powers from the Greek Gods. Her mom's a museum curator and can literally ground Cass. She's sassy, and packs a good punch, but unfortunately doesn't always think before she opens her mouth. In early, YJ days she wore a black wig but has pared down the costume and seeing if blonde's have more fun after all. Some people suspect, she lost IQ points when she lost the wig. Of course, that's just a vicious rumor.
Cissie King-Jones a.k.a. Arrowette... quit YJ after an impulsive moment, almost killing a man. Her mom was the original sidekick and Cissie's been living out her dream. Ciss is the most dynamic in her roles. She's an Olympic Gold Medalist, an actress, and a medic. She acts and looks mature for her age and even though she quit, she's in nearly every issue.
Greta a.k.a. Suzie a.k.a. Secret... is the dead mist-like girl. She's the sister to a YJ baddie. She's slightly nuerotic and obsessive (mostly about Robin). She's optimistic, usually happy, when she's not having crazy mood swings. She lives in the real world and teters on the border to the next life. One moment she's cute and innocent, the next she's swallowin' ya whole. Don't get her mad. It ain't pretty.
Anita Fite a.k.a. Empress... is the daughter of Agent Fite from the APES department. 'Nita, as she's usually called, packs a token accent, a very sharp stick, and a bunch of mega-impressive voodoo powers. She was a fan girl, inspired by Cissie, who managed to bail YJ out of scrapes before becoming an official member of the team.
Slo-bo a.k.a. Li'l Lobo... was originally the Main Man and then he ran into the Witch Boy who de-aged him. So where was a teenage Lobo to go? He eventually ran into some teen heroes, then the YJ group. He's stuck around not really official, and for the longest time YJ didn't know what to do with him. He's recently morphed again, becoming an even scrawnier version of himself. Still, don't let his appearance fool you, he can still frag with the best of 'em.
Red Tornado... is an android with emotions. He has a wife, Kathy, and a daughter, Traya. He took a leave of abscene from the JLA and found himself babysitting a group of teen superheroes. He's more of a chaperone rather than a leader of the team.
Carol Bucklen a.k.a. Carol Trent (editing snafu)... is/was one of Bart's classmates. She's a bit homely, but still mega cool. She's stood up to law and helped Bart when he was still adjusting to small town life. Carol is Bart's voice of reason and his first kiss. She figured out he's Impulse and also become a confidant as well as a girlfriend(!) Currently, she's stuck in the future for reasons having to do with the fate of the universe (tm). Needless to say, her and Bart won't be hanging out any time soon.
Tana Moon... was a reporter in Hawaii and The Kid's main flame. They were perfect and cute, and totally touching. Sure, they had their ups and downs but what relationship didn't? Unfortunately, it all came to an end when Evil Amanda Spence killed Tana during the Sins of Youth arc. Kon's never quite gotten over her, and I'm not sure he ever will.
Hawaii... was Kon-El's stomping ground for a very long time. He had an agent, a few girl friends, a few girl enemies.
Cadmus... is the organization that Kon used to work for. Here he got to harrass Gaurdian (Roy Harper's kinda uncle) and Serling and Mickey, among others. Recently, it's been disbanded and Kon's been by himself, somewhere around Metropolis to boot.
Happy Harbor... is the ex-JLA headquarters. Located in Rhode Island, it was where YJ originally had their HQ.
Pennsylvania... is the current HQ of YJ. The land's owned by Bruce Wayne's corporation and it's pretty much a giant house in the middle of nowhere. They need the space after all, they have the supercycle and Bart's spaceship and... well, you get the idea.