The Mediator Series by Meg Cabot
I discovered this series while waiting the seemingly countless hours at the midnight release of Harry Potter and the Half Blood Prince. I probably read the back of every single YA book in my bookstores small section, and these stood out the most, so I got the first few. After I devoured those I HAD to have rest.
The Mediator Series is about a girl, Suze, who moves to Northern California and finds a ghost living in her bedroom. Suze has always been able to see ghosts, but in New York there aren't all of the old buildings that people probably died in like there are in Northern California. When she goes to her knew school she finds out that her Principal can also see ghosts, or is a "mediator" as he calls it. He tells her that their job is to help send souls to the other side.
Now, Suze isn't your usual, whiny, damsel in distress type of girl. She's your kick butt, fend for herself, doesn't take any crap type, and I totally want her as a best friend. She's probably the main reason why I like these books so much. Well, Jesse, the totally hot ghost living in her bedroom, helps too.
Basically over all six books Suze helps a few souls, get's herself in trouble, solves a few mysteries, makes some good friends, and falls in love. The books are awesome. They're basically everything that you could want in a series times ten. Action? Adventure? Romance? Mystery? Suspense? Wit? Snappy Comebacks? Ghosts? Hilarity? They've got it all, they're just waiting for you to pick them up and read them. You won't be disappointed.