One gives direction to put name to letters (8)
I believe the answer is:
signpost
'one gives direction' is the definition.
'put name to letters' is the wordplay.
'put name to' becomes 'sign'.
'letters' becomes 'post' (I've seen this before).
'sign'+'post'='SIGNPOST'
'to' is the link.
(Other definitions for signpost that I've seen before include "It shows the way" , "pointer along the way" , "indication how to progress" , "Clue" , "Guide, indicator" .)