Heads offering some children odd lessons (7)
I believe the answer is:
noddles
'heads' is the definition.
(noddle is a kind of head)
'some children odd lessons' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'NODDLES' is hidden within 'children odd lessons'.
'offering' acts as a link.
(Other definitions for noddles that I've seen before include "beans" , "Heads (sl.)" .)