Training at Eagle was conducted like this:
A student goes through the 4 week training class, and does not step foot on a real airplane. Students are fully trained via cabin trainer to conduct emergency evacuations. Upon graduation, new-hires report to base where they undergo what is called IOE, or Initial Operating Experience.
During IOE the new-hire flies with a designated IOE instructor (which I was for 3 years). The student is paired with the instructor, on the instructors bid line trip. The instructor MUST occupy the F/A jumpseat, as the new-hire is not yet fully qualified. During IOE the student occupies a passenger seat for take-off & landing. I would try very hard to get them in the seat closest to me, so I could hand them the PA to make announcements, and so they didn't have to be climbing over paying pax to work the flight. How I conducted IOE was the first flight I did everything and had the student watch, then starting with the second trip I gave them more and more duties until the last flight when they must do everything all on their own, and that is their checkride. They must complete all duties with no assistance to pass this ride. As long as they have logged enough hours (about 8 hours, I'd have to check my paperwork to tell you exactly how many hours are required per FAA) I would sign them off, and then they were on their own! The FAA says "props" and "jets" are two separate types of aircraft, and you have to log a certain amount of hours on a "jet" (either the EMB or CRJ), and a certain amount of hours on a "prop" (either the ATR or Saab). So a new-hire will usually end up doing two trips, with two different instructors before they're done with IOE. I tried to resign as an IOE instructor, but the training department wouldn't let me because I was the only instructor in ORD who bid the ATR. I had a student with me on every trip until the ATRs left ORD.
At AA we did work flights while in ground school, so there was no IOE required. There are extra F/A jumpseats on all AA aircraft, and before we worked a trip on a certain ac we had to have completed the cabin trainer evacuation drills & related exams.
Hope this answers your question!