Reading into the fantastic reality of books (8)
I believe the answer is:
literary
'of books' is the definition.
(I've seen this before)
'reading into the fantastic reality' is the wordplay.
'reading' becomes 'r' (one of the traditional three R's of education).
'into' is an insertion indicator.
'the fantastic' is an anagram indicator (a fantastic or improbable ordering of the letters).
'reality' with letters rearranged gives 'literay'.
'r' going into 'literay' is 'LITERARY'.
(Other definitions for literary that I've seen before include "Relating to writing of artistic merit (8)" , "The scholarly type" , "Of or concerned with good books and writing" , "Concerning writing of artistic value" , "Indicates writing of artistic value" .)