Shadowland (Mediator, 1) by Jenny Carroll
Reading level: Young Adult
"You're dead. You don't belong here."
Susannah just traveled a gazillion miles from New York to California in order to live with a bunch of stupid boys (her new stepbrothers). She hasn't even unpacked yet, she's made her mother practically cry already, and now there's a ghost sitting in her new bedroom. True, Jesse's a very attractive guy ghost, but that's not the point.
Life hasn't been easy these past sixteen years. That's because Susannah's a mediator -- a contact person for just about anybody who croaks, leaving things...well, untidy. At least Jesse's not dangerous. Unlike Heather, the angry girl ghost hanging out at Susannah's new high school....