The 41-year-old Ellison, who sought the position, said he will not get paid for coaching.
Ellison is nicknamed "Never Nervous Pervis" for his stellar play at the University of Louisville. As a freshman center, he led the Cardinals to the 1986 NCAA championship and was named most outstanding player for his efforts.
Following his career as a four-year starter, Ellison was the first overall pick, by the Sacramento Kings, in the 1989 NBA draft.
The 41-year-old also had stops with the Washington Bullets, Boston Celtics and Seattle SuperSonics before injuries forced his retirement in 2000.
"For someone like Pervis to call us, that says a lot about the kind of person he is," said Jim Pepper, the athletic director at New Beginnings. He and Ellison have mutual friends, which led to Ellison's joining the coaching staff.
Gary Daniels is the head coach of the boys' varsity high school team.
Contact staff writer Keith Pompey at 610-313-8029 or kpompey@phillynews.com.