Beaglehole's playing career included appearances for England at Under-18 and Under-19 level and he turned out in the reserves for Barnsley and Sheffield United.
Beaglehole holds a degree in Sports Science and is also a qualified Physical Education teacher. He became the youngest person to obtain the 'A' licence badge at the age of 21.
His managerial experience included leading the Doncaster Rovers, his hometown team, between 1991 and 1993. He joined Leicester City in October 2000 to work in the Academy and has worked with Jon Rudkin to recruit some strong young players.
After holding youth team coaching positions at Doncaster Rovers and Middlesbrough, Beaglehole became reserve team coach at Nottingham Forest and Leeds United, where he worked with Alan Hill, the former Leicester Academy Director.
He was promoted from youth coach after the departure of boss Billy Bremner and was one of the youngest managers in the league, younger even than some of his players. In his only full season in charge, the team finished five places higher in Division Three so progress had been made. One of his highlights there was guiding the team to the FA Youth Cup Final against Arsenal.
From the start of the 2012-2013 season Beaglehole took charge of Leicester City new 'development squad' which takes part in the Under-21 Professional Development League 2 North division. The team won 9 out of their first 12 games before Christmas 2012, sitting top of the league going into the new year. The team eventually went on to comfortably win the league with a game to go, but subsequently lost the national play-off semi-final to Cardiff City. Beaglehole and Jon Rudkin then took a team of under-21 and under-18 players to the end of season HKFC International Soccer Sevens tournament, winning the competition thanks to a 2-0 victory over Newcastle United in the final.
His son Shamus Beaglehole (Born 1 March 1993 in Doncaster) joined Chesterfield as a scholar in the summer of 2009. He plays in midfield and had been at Doncaster Rovers centre of excellence.
In April 2014 Shamus won Name of the Year.