"House of Night series" by P.C. and Kristin Cast
We have all six books in the series, the first one is "Marked"
In 16-year-old Zoey Redbird's world, vampyres not only exist but are also tolerated by humans. Those whom the creatures "mark" as special enter the House of Night school where they will either become vampyres themselves, or, if their body rejects the change, die. To Zoey, being marked is truly a blessing, though she's scared at first. She has never fit into the human world and has always felt she is destined for something else. Her grandmother, a descendant of the Cherokee, has always supported her emotionally, and it is she who takes the girl to her new school. But even there the teen stands apart from the others. Her mark from the Goddess Nyx is a special one, showing that her powers are very strong for one so young. At the House of Night, Zoey finds true friendship, loyalty, and romance as well as mistrust and deception. She realizes that all is not right in the vampyre world and that the problems she thought she left behind exist there as well
Mortal Instruments trilogy by Cassandra Clare
The first book is "City of Bones"
When Clary Fray witnesses three tattoo-covered teenagers murder another teen, she is unable to prove the crime because the victim disappears right in front of her eyes, and no one else can see the killers. She learns that the teens are Shadowhunters (humans who hunt and kill demons), and Clary, a mundie (i.e., mundane human), should not be able to see them either. Shortly after this discovery, her mother, Jocelyn, an erstwhile Shadowhunter, is kidnapped. Jocelyn is the only person who knows the whereabouts of The Mortal Cup, a dangerous magical item that turns humans into Shadowhunters. Clary must find the cup and keep it from a renegade sector of Shadowhunters bent on eliminating all nonhumans, including benevolent werewolves and friendly vampires.