You don't need a book. The answers are in the music. Transcribe and learn fills you dig.
A few recommendations:
Ringo Starr
Jeff Porcaro
Steve Gadd
Dom Famularo
Bernard 'Pretty' Purdie
Jim Keltner
Also, write your own. Write out as many rhythmic patterns as you can think of and then orchestrate them on the kit in various ways.
I often come up with fills based on what's going on in the music. For example, if I'm recording an original song and the artist wants a big fill going into the chorus, I'll listen to what the melody is doing and create a fill that relates. This ensures that the fill is both appropriate and interesting. Same goes for filling at the end of a solo (for example, the end of a guitar solo going back into the last verse or last chorus etc.). Listen to what the soloist is playing and play a fill that relates to the idea he/she is performing at the end of the solo.