Inform about best form of yelling (9)
I believe the answer is:
screaming
'form of yelling' is the definition.
'screaming' can be an answer for 'yelling' (I've seen this before). I am unsure of the 'form of' bit.
'inform about best' is the wordplay.
'inform' becomes 'sing' (I've seen this in other clues).
'about' is an insertion indicator.
'best' becomes 'cream' (both can mean the elite).
'sing' enclosing 'cream' is 'SCREAMING'.
Can you help me to learn more?
(Other definitions for screaming that I've seen before include "Uttering sharp piercing cries" , "Shrieking" , "Yelling" , "Emitting sharp, piercing cries" .)