Terry Pratchett 
Mort 
(Discworld Novel 4)

”YOU CANNOT INTERFERE WITH FATE. WHO ARE YOU TO JUDGE WHO SHOULD LIVE AND WHO SHOULD DIE?”
Death comes to us all. When he came to Mort, he offered him a job.
Death is the Grim Reaper of the Discworld, a black-robed skeleton with a scythe who ushers souls into the next world. He is also fond of cats and endlessly baffled by humanity. Soon Death is yearning to experience what humanity really has to offer, but to do that, he”ll need to hire some help.
It”s an offer Mort can”t refuse. As Death”s apprentice he”ll have free board, use of the company horse – and being dead isn”t compulsory. It”s a dream job – until Mort falls in love with Death”s daughter, Ysabell, and discovers that your boss can be a killer on your love life . . .
”Incredibly funny, compulsively readable” The Times
”Cracking dialogue, compelling illogic and unchained whimsy” Sunday Times
Mort is the first book in the Death series, but you can read the Discworld novels in any order.