Our youngest rimmer is 24 and was hired out of college. Others moved from different teams, or were new hires. We use Atex and Press2Go. We don't really try out candidates, aside from interviews and a copy editing test. We do, however, sometimes hire interns and temps.
Computer training is available to everyone.
As far as copy editing training goes, it's usually the slot's responsibility to coach new editors. Most work five days a week and have set schedules. Normal hours are 4 p.m. to midnight. There is a lot of flexibility on the Night GA team, and I think in the newsroom in general. Some people work part-time, and personal issues and child care needs are taken into account.