Resort book's absolutely correct (8)
I believe the answer is:
brighton
'resort' is the definition.
(seaside resort)
'book's absolutely correct' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'absolutely correct' becomes 'right-on' (I've seen this before).
'b'+'righton'='BRIGHTON'
(Other definitions for brighton that I've seen before include "Graham Greene wrote ` `........ Rock' '" , "South coast city combined with Hove" , "Where the Prince Regent built his Pavilion" , "... hard cylindrical sweet from the seaside" , "Resort on the south coast of England" .)