Each little segment is a separate comp within the same project. The project contains all of your source media and resources. You will assemble the smaller bits into your longer timeline in Premiere, most likely. It can be done in AE but AE is not a convenient editor.
Not sure what exactly you think you need to know. I see this is your first post, is this your very first AE project? Flash only vaguely resemble After Effects, you have mucn to unlearn just to get to appreciating the differences.
Message was edited by: bogiesan
I would typically divide my project into smaller compositions, then nest those compositions into one final comp for rendering. In particularly complex jobs you may choose to pre-render some components. See Precomposing, Nesting and Pre-rendering.
Thanks very much Andrew that has helped a lot, I have a feeling I will be on this forum quite a bit!!
Thanks Boglesan, yes this is my first project and you are right the two are different beasts!, There are real similarities regarding the creation workfow though. However I would rather not leave the AE app if possible.