The box will convey information to a youth leader (5)
I believe the answer is:
telly
'the box' is the definition.
(both can mean a television set)
'will convey information to a youth leader' is the wordplay.
I cannot really see how this works, but
'will' could be 'll' (contracted form, as in 'he'll' - 'he will') and 'll' is present in the answer.
'youth' could be 'y' and 'y' is present in the answer.
'leader' could be 'e' (I've seen this in other clues) and 'e' is located in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for telly that I've seen before include "'The box' (colloquial)" , "Set" , "The goggle-box" , "TV (colloq.)" , "Television" .)