Teenage leader of the Kyoshi Island warriors, Suki is strong, intelligent, and takes her island's traditions very seriously. She's courageous in battle and is quite skilled in Kyoshi's style of martial arts, which involves using fans as a weapon. While confidant in herself, she doesn't have an inflated ego.
Suki and Sokka clashed at first, mainly because of Sokka's chauvinist attitude towards women. After putting him in his place in front of the other Kyoshi Warriors, and later when Sokka humbly asked for her to train him, she agreed despite the center's rule to not train boys. During their training session they grew friendlier, and almost trusting in each other as they fought against Prince Zuko when he invaded the island. Before Sokka fled with Aang and Katara, Suki kissed him on the cheek. Judging by the way the he blushed, it was probably one of his first kisses. ^-^
Contributed by Sarah of Airbender.net:
Suki returned in episode 212 "The Serpent's Pass". When Aang's group first visited Kyoshi Island, they had made a big impact on her, so she and the Kyoshi Warriors traveled to Ba Sing Se to help in the war. They ended up working as security guards in the passport office outside the city, after they had escorted some refugees there.
She crossed the Serpent's Pass with Sokka and group to make sure they got across safely. Because Sokka felt guilty about his past relationship with Princess Yue, in which he was convinced that he failed to protect her, he was very overprotective of Suki. Although at first he didn't want to get into a relationship with her, Suki still liked Sokka. By the end of their time together Sokka decided to move on and he ended up kissing her.
At the end of the trip, Suki returned to the Kyoshi Warriors, but she reappeared again in episode 215, "Appa's Lost Days". She stumbled upon an injured and frightened Appa in the woods, and with the help of the other Warriors was able to clean and feed him. Then however, Azula and her gang who had been tracking Appa by his clumps of fur, attacked. Appa escaped, but Suki's fate remains uncertain.