Dead Witch Walking (Rachel Morgan Series #1) by Kim Harrison

Rachel Morgan is on the run with a contract on her head. To clear her name, Rachel must evade shape-changing assassins, outwit a powerful businessman/crimelord, and survive a vicious underground fight-to-the-death. Fun, sassy, filled with action, humor, and romance, Dead Witch Walking is perfect for anyone who likes vampires, paranormal fantasy, romance, or just a great beach book.