Book edited by an old guy who usually writes his own stuff (3,5)
I believe the answer is:
bob dylan
'guy who usually writes his own stuff' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'book edited by an old' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'edited' indicates anagramming the letters.
'by'+'an'+'old'='byanold'
'byanold' is an anagram of 'obdylan'.
'b'+'obdylan'='BOB DYLAN'
Can you help me to learn more?
(Other definitions for bob dylan that I've seen before include "US protest singer/songwriter" , "Singer-songwriter, born Robert Allen Zimmerman in 1941" , "US singer/songwriter is nobly bad, curiously" , "Songwriter, winner of the 2016 Nobel Prize for Literature" , "Singer" .)