Best put paper under contract at first (5)
I believe the answer is:
cream
'best put' is the definition.
'cream' can be an answer for 'best' (thesaurus). I'm not certain of the 'put' bit.
'paper under contract at first' is the wordplay.
'paper' becomes 'ream' (I've seen this before).
'under' means one lot of letters go next to another.
'at first' indicates taking the first letters.
The first letter of 'contract' is 'c'.
'ream' put after 'c' is 'CREAM'.
Can you help me to learn more?
(Other definitions for cream that I've seen before include "treat for cat?" , "The best part -of the crop" , "Best part of the milk" , "Butterfat part of milk" , "Top or best part" .)