Don't go so fast providing son with information (4,4)
I believe the answer is:
slow down
'don't go so fast' is the definition.
(I've seen this before)
'son with information' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'with' says to put letters next to each other.
'information' becomes 'low-down' (the low-down can mean information or news).
's'+'lowdown'='SLOW-DOWN'
'providing' acts as a link.
(Other definitions for slow down that I've seen before include "take it more easy" , "Don't go so fast" , "Reduce speed" , "Lose velocity" , "relax" .)