Prepare cooking here, putting in some corn (8)
I believe the answer is:
rehearse
'prepare' is the definition.
(I've seen this before)
'cooking here putting in some corn' is the wordplay.
'cooking' is an anagram indicator.
'putting in some corn' becomes 'arse' (I can't justify this - if you can you should give a lot more credence to this answer).
'here' with letters rearranged gives 'rehe'.
'rehe'+'arse'='REHEARSE'
Can you help me to learn more?
(Other definitions for rehearse that I've seen before include "Practise - run through" , "Train" , "Practise play in theatre" , "Practise before a public performance" , "What actor does to prepare for play" .)