I've so far dabbled in Flash doing 1-man shows for quite some time, but have never done any big projects with it, where actually source management and code-reuse was truly necessary. However I'm considering Flash for a new project, but this time around it's won't be a 1-man show, that's when it struck me that I had no experience of how one is supposed to do that with flash.
What are some good tips or resources that could help us figure out a good workflow?
With junior developers it's also good to go through basic stuff such as package structures etc, just so that everybody is on the same page.
I think it's also good if somebody is kind of like a technical manager of the project, overseeing what the developers are doing. It may also be one of the developers but i think it's important to have one person who knows what everybody else is doing.
Antti has a bunch of good ones, externalizing code and appointing a leader in particular, I'd just add that when you're picking different tasks for everyone, tell people to code their piece as a modular class that provides the functionality you'll need - that'll make the code more reuseable in the future, and make integration smoother as well.