Little runner putting papers at bottom of road (6)
I believe the answer is:
stream
'little runner' is the definition.
'stream' can be an answer for 'runner' (I've seen this in another clue). I'm not sure about the 'little' bit.
'papers at bottom of road' is the wordplay.
'papers' becomes 'ream' (a ream is a large amount of paper).
'at bottom of' means one lot of letters go next to another (in a down clue, some letters go underneath others).
'road' becomes 'st'.
'ream' put after 'st' is 'STREAM'.
'putting' acts as a link.
Can you help me to learn more?
(Other definitions for stream that I've seen before include "Torrent" , "Small narrow river" , "Brook or rivulet" , "Constant flow of liquid" , "Transmit music or video online" .)