I noticed a search on "history of inverell" that brought the searcher to one of my posts, New history of Inverell's Byron Arcade . There was one link there that might have been helpful, but I though it worthwhile to do a short follow up post.
So far as the internet is concerned, Inverell On-line has a very useful local history page. Then Elizabeth Wiedamann has written two very useful books.
The first, World of its Own, covers the history of Inverell up to 1920. The second, Holding its own: The Inverell District since 1919, covers the later period.
The Inverell Genealogical & Historical Society site is also worth a visit.