Daughter of Hades by Helen Scott

Poppy never thought her life would get this crazy.
Sexy hellhound guards and being the future queen of the Underworld? She had been happy being a waitress and a freelance graphic designer in Chicago, hadn’t she? What she was doesn’t matter, that life is long gone now.
Before she can travel to the Underworld, she needs to find three judges that will preside over the souls of the dead. But who are they? Where are they? And how the hell is she supposed to find them?
As she battles agents of Hel at every turn and is confronted with mysterious new enemy Poppy is decidedly on edge. Will she find her judges in time or will her enemies get to them first?