The Dragon Tax - Dragonsbane Saga, #1

The only thing more dangerous than trying to kill a dragon is trying to make one pay taxes. One doesn't turn down a king, so Sybil accepts the job despite her misgivings. Usually she's slaying dragons, not talking to them. Instead of collecting the tax, she unknowingly delivers a curse that leaves the dragon helpless, and she can't bring herself to slay him. Trapped in a body not his own, the dragon Riastel is scared and defenseless.
Sybil finds him charming, in a brutish way. Unwilling to turn him over, Sybil and Riastel are wanted, on the run, and worse? Sybil may be falling in love.