Ryan Air takes low time pilots with a Commercial ticket and puts them in the right seat of a CASA 212 for a year, then moves them to the C-207. From there you are eligible to move into the Skyvan or back to the CASA.
Era hires low time pilots into the right seat of the Caravan. After accumulating enough hours (I can't recall the figure, but it's in the range of 1000 - 1200) you go to the C-207. Era (which operates under two or three certificates due to the acquisition of Hagelands and Frontier) has a varied fleet, so you could eventually go into a Navajo, a Caravan, a King Air, or a Conquest.
I don't know if Grant or Bering Air have similar programs, but it wouldn't surprise me.
Yute hires lots of low time people, but they fly in all but the worst weather. Pretty much considered the employer of last choice.
Bush flying is really great, but I wonder if it's the right fit for people aiming on the majors. It's perfect for the type of person who loves to fly for the sake of flying and for the person who likes the Alaska lifestyle. It's not right for the person who is expecting predictability in his schedule or operations, terrific living conditions, a mild climate, or spit and polish planes. However, it is exactly the right thing for some of us.
If you are the more adventurous type you should look into it. Don't bother mailing or emailing resumes: they won't get you a job. Instead, go to Anchorage with a stack of resumes and make the rounds. Speak to the Chief Pilot (he will almost always talk to you if he's in town).
Good luck
Panzon