Coleman was born in Forest Gate, a suburb in east London. Not long after he was born, his family moved a few miles east to Barking. At the time of his arrival, the area was just starting to recover from the damage it had received during World War II. He lived in a house on Bevan Avenue, named after Aneurin Bevan the architect of the National Health Service. He lived in that estate for 20 years. The area helped develop Coleman's love of sport due to the oblong shaped lanes of grass leading up the estate, which could be used as mini-stadiums. He pretended to play at various sporting events of the time, e.g. the Melbourne Olympics of 1956, the soccer Cup Final at Wembley Stadium, and the games at Lords Cricket ground. He still has medals he won for being school champion in the 100m sprint and the long jump. As said by Coleman himself "My information series Foul Football tries to convey some of the magic I felt about the game of soccer by relating the weird and wonderful history of the game and the personalities it has seen over the years. On the fiction side, my series about a junior soccer team called Angels FC tries to bring out the humour and sheer fun that you’ll find at the heart of the game when it’s played by youngsters who don’t even know how to spell the word cynicism." Coleman had his first children’s book published when he was 46 years of age. He has also said: "I didn't [want to become a writer] at first. I used to teach computer science at a university and my first book was a boring one about computers. I livened it up by putting a few jokes in. At the end I thought I'd try writing a few more things, but this time forgetting about the computers and concentrating on the jokes. After lots of failures I realised that youngsters enjoy jokes more than adults and started writing for them. Eighty books later, I'm still doing it...I write both fact and fiction. The Foul Football series are favourite fact books, simply because they're about football. On the fiction side, I'm just finishing a trilogy called The Bearkingdom. They're dark and scary, quite different to anything I've written before."