Hermione and Ron, along with Draco and Padma, sat their N.E.W.T.'s idly a few days after Harry's funeral, while rain poured from the sky, and Ginny, claiming the sky was crying with them, sat out near the lake, returning with muddy robes and puffy eyes. All four of them passed, and graduated from Hogwarts-- Hermione with flying colors, of course.
The Death Eaters that were not killed in the battle were sent to Azkaban Prison. No one had thought to take the Cruciatus Curse off of Lucius Malfoy, and he was tortured into insanity; however, instead of being sent to St. Mungo's, he was sent to the criminally insane ward in Azkaban.
Draco Malfoy took up the position as Defense Against the Dark Arts teacher, immediately after Eva Wingfield decided to go back into retirement. He married Hermione, who joined the Ministry and was a big part of its reform, striking down things like anti-
Ron went to work for the Ministry, taking a position in the Department for International Magical Cooperation, while Padma became an alchemist. They also got married.
Neville spent hours with his parents, and also saw plenty of Luna. He worked at an apothecary, where all his genius in Herbology finally came to fruition, as he discovered an herbal therapy for insanity, and is currently working to nurse his parents to health. Luna, meanwhile, worked as a Healer at St. Mungo's until she took over The Quibbler.
Tonks and Lupin never officially married, but they lived together for the rest of their lives. Tonks remained an Auror; Lupin came back to Hogwarts as Headmaster after Minerva McGonagall passed away in her sleep.
Sirius became an Unspeakable at the Department of Mysteries, his name officially cleared, and worked until the end of his days in the Death Chamber, striving in vain for a way to bring Harry back.
And Ginny joined the Aurors, eventually becoming the head of the department. She looks in the mirror before going to work every morning, and always wears her hair pulled back, so that she can see her reminder-- so that she can see her scar.