Organise letter spread (7)
I believe the answer is:
arrange
'organise' is the definition.
(arranging is a kind of organizing)
'letter spread' is the wordplay.
'letter' becomes 'ar' (I can't justify this - if you can you should give a lot more credence to this answer).
'spread' becomes 'range' (I've seen this in other clues).
'ar'+'range'='ARRANGE'
Can you help me to learn more?
(Other definitions for arrange that I've seen before include "Put in order; make plans" , "Plan, organize" , "Bring about or put in order" , "Orchestrate - order" , "Put in systematic order" .)