Conventional piece of work, a book about the North (8)
I believe the answer is:
ordinary
'conventional' is the definition.
(thesaurus)
'piece of work a book about the north' is the wordplay.
I cannot quite understand how this works, but
'piece' could be 'r' (abbreviation for Rook) and 'r' is located in the answer.
'of' could be 'o' and 'o' is found within the answer.
'a' is within the answer.
'north' could be 'n' (abbreviation) and 'n' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ordinary that I've seen before include "Workaday" , "Not worthy of noting in X-Files" , "One entitled to try" , "Common-or-garden" , "simple charge" .)