Notions partly guide assistants (5)
I believe the answer is:
ideas
'notions' is the definition.
(I've seen this in another clue)
'partly guide assistants' is the wordplay.
'partly' indicates the answer is hidden within the clue (part of the clue is used).
'IDEAS' is hidden within 'guide assistants'.
(Other definitions for ideas that I've seen before include "Thoughts, concepts" , "Thoughts, creative perhaps" , "Thoughts from Sadie" , "Brain waves" , "Theories" .)