Actually, Prince started out as a go-fer and assistant for the legendary director George Abbott. Abbott taught him the business end of the theatre and after serving as stage manager for a couple of Abbott shows (the original productions of "Call Me Madam" and "Wonderful Town"), Abbott put him in charge of producing his shows (Prince had no money of his own, but had something FAR better -- Abbott and the list of folks dying to put their money into a George Abbott-directed show). He produced "Damn Yankees," "Pajama Game" and "New Girl In Town" which were all directed by Abbott as well as being huge Tony Award winning hits. This allowed him to branch out on his own and the next year he produced "West Side Story" (and we all know what happened with that). He went on and produced a few more Abbott hits -- "Tenderloin," "Take Her, She's Mine" and "A Funny Thing Happened On the Way To the Forum" -- as well as the Robbins classic "Fiddler On the Roof," until he decided to take on directing chores himself in the early 60's. His first hit as director and producer was "She Loves Me" and he wore both hats for most of the rest of his career in the 60's, 70's and beyond (including "Cabaret" and all of Sondheim's work from 1970's "Company" to 1981's "Merrily We Roll Along"........ as well as last year's "Bounce").
Interning for a producer is an excellent way to learn the business. There are also some very good "Producing In the Theatre" seminars that happen each year that you should look into. If I were you, I would write letters to all of the major off-Broadway & Broadway producers -- Daryl Roth, Chase Mishkin, Arlene Tepper, Roger Berlind, Margo Lion, Roy Gabay, et al (there are dozens) and express your interest, and ask them for their advice (and maybe an internship). At the very least, you should get a nice form letter back with some good ideas, but some of them I'm sure will have some concrete, personal advice for you. The list of all the major producers and their contact info is in the Theatrical Index (I think that's what it's called) which you can get from the Drama Bookshop -- call them up and explain what you're looking for and trust me, they'll know. Good luck.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney