Notice which might upset you a bit? That's about right (8)
I believe the answer is:
obituary
'notice which might' is the definition.
'obituary' can be an answer for 'notice' (I've seen this before). I'm not certain of the rest of the definition.
'upset you a bit? that's about right' is the wordplay.
'upset' indicates anagramming the letters.
'that's about' is an insertion indicator.
'right' becomes 'ar' (I can't justify this - if you can you should believe this answer much more).
'you'+'bit'='youbit'
'youbit' with letters rearranged gives 'obituy'.
'obituy' enclosing 'ar' is 'OBITUARY'.
Can you help me to learn more?
(Other definitions for obituary that I've seen before include "Brief newspaper account of life of notable deceased" , "Brief newspaper account of dead person's life" , "Brief tribute written to someone who has died" , "Account of a life after death" , "Announcement of death with short biography" .)