He was one of the most prolific non-league goalscorers in history, with over 500 goals to his name in a career spanning almost two decades. This success saw him play for the England National Game XI (the England team for semi-professional players) and receive many Player of the Year awards from the clubs he played for.
He was appointed player-manager of Ashton United in 1997. After two years, he joined Accrington Stanley then playing in the Northern Premier League First Division. His 12-and-a-half-year tenure saw the club win three promotions as champions to enter the Football League in 2006. He was also the club’s longest ever serving manager. At the time of his departure to Rochdale, Coleman was the third longest serving manager in England, behind Sir Alex Ferguson and Arsene Wenger.
On 24 January 2012, Coleman and his assistant Jimmy Bell were appointed by Rochdale to replace Steve Eyre, who had left the club the previous month. Their contracts were terminated by Rochdale on 21 January 2013 following a poor run in form. 
John returned to Southport FC as manager on 7 December 2013