He brings a bit of joy to a redhead (3)
I believe the answer is:
roy
'he' is the definition.
'a bit of joy to a redhead' is the wordplay.
'a bit of joy' becomes 'oy' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to a' means one lot of letters go next to another (I've seen this in other clues).
'redhead' becomes 'r' (head letter of 'red').
'oy' after 'r' is 'ROY'.
'brings' acts as a link.
Can you help me to learn more?
(Other definitions for roy that I've seen before include "Rob --, Scots outlaw" , "Rob .... was a famous Scottish bandit" , "'... Rogers, old film star cowboy (3)'" , "-- Lichtenstein, US artist" , "Man" .)