Behave yourself when you act as guide (7)
I believe the answer is:
conduct
'behave' is the definition.
(I know that behave can be written as conduct)
'yourself when you act as guide' is the wordplay.
I cannot really see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is found in the answer.
'you' could be 'u' (commonly used in online communication) and 'u' is found in 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 conduct that I've seen before include "Guide - behaviour" , "Behaviour; transmit" .)