Author keeps first of his books here? (5)
I believe the answer is:
shelf
'books here?' is the definition.
(I've seen this before)
'author keeps first of his' is the wordplay.
'author' becomes 'self' (novelist Will Self).
'keeps' indicates putting letters inside (inserted letters are kept inside).
'first of his' becomes 'h' (sst letter of 'his').
'self' enclosing 'h' is 'SHELF'.
(Other definitions for shelf that I've seen before include "sort of life" , "Horizontal surface for holding things" , "Ledge on which to stand items" , "grass down under" , "Projecting layer of rock" .)