How does a broadway musical audition work?

This next week I'm auditioning for two equity off broadway musicals in New York. I'm not an equity actor or part of any union. From my simple understanding I know that I will only be seen if time allows and they want to see non-equity. The audition info says auditions are from 10AM - 6PM but I read somehwere that you should show up at 5AM to sign up for an audition. I also heard they line you up and based on if your look is right for the show, they'll let you audition (equity or not). Is that right? I'm totally clueless about the process so if you could map it out that would be great. Thanks!