One of the television programs I'm avidly watching presently is The Secret Circle.  This particular series is written by L.J. Smith (same author of Vampire Diaries) and I am hooked! 

As a brief synopsis, a teenage girl (Cassie Blake) gets a flat tyre as she's returning home.  She calls her mother to let her know what's happening and the phone goes dead.  Outside a mysterious man causes Cassie's mother to die in a fire and Cassie goes to live with her grandmother, sparking a whole series of events which culminate in her finding out she is a witch.  Cassie is not the only witch, however, and soon she finds herself bound in a "circle" with five other teens and a bevy of problems to face, not all of which are supernatural in origin!  Cassie's friend (and fellow circle member) Diana has some lovely family members.  I thought her father was bad, but her grandmother is a real treasure who tries to kill Cassie. 

Other teen witches include the self-absorbed and totally reckless Faye, who tries to steal Cassie's magic, and ends up nearly killing the rest of the circle instead.