Start writing about Iron Age hilts, oddly (9)
I believe the answer is:
originate
'start' is the definition.
(I know that start can be written as originate)
'about iron age hilts oddly' is the wordplay.
'about' indicates an anagram.
'oddly' means one should take alternating letters (letters in odd-numbered positions).
The alternating letters of 'hilts' are 'it'.
'iron'+'age'+'it'='ironageit'
'ironageit' anagrammed gives 'ORIGINATE'.
'writing' acts as a link.
(Other definitions for originate that I've seen before include "Cause to begin, be the first" , "Set up" , "Found" , "Launch" , "Create, initiate" .)