Candid guide (6)
I believe the answer is:
direct
I believe this clue is a double definition.
'candid' is the first definition.
(similar in meaning)
'guide' is the second definition.
(I know that guide can be written as direct)
(Other definitions for direct that I've seen before include "Straightforward, frank" , "Guides do it" , "Straight; manage" , "Take charge, of a company or film say" , "Control the affairs" .)