Book on small creature not all my own work (3,5)
I believe the answer is:
job share
'not all my own work' is the definition.
(a job share means shared work)
'book on small creature' is the wordplay.
'book' becomes 'Job' (book of the Bible).
'on' is a charade indicator (letters next to each other).
'small' becomes 's' (abbreviation - e.g. clothes size).
'creature' becomes 'hare' (type of animal).
'job'+'s'+'hare'='JOB SHARE'
(Other definitions for job share that I've seen before include "halve the workload" , "Some part-timers do" , "Arrangement between two workers" , "Split post" , "Divide work up" .)