Everybody is about to read 'Coral Island' (5)
I believe the answer is:
atoll
'coral island' is the definition.
(I've seen this before)
'everybody is about to' is the wordplay.
'everybody' becomes 'all' (all people).
'is about' means one lot of letters goes inside another.
'all' placed around 'to' is 'ATOLL'.
'read' acts as a link.
(Other definitions for atoll that I've seen before include "Ring-shaped coral reef enclosing a lagoon" , "Bikini, say" , "Allot (anag.)" , "Circular coral reef" , "Coral circle" .)