Making a full flash site - organization

I’ve decided to finally make my own full flash site. I’ve got more than enough Flash and ActionScript (and XML) knowledge to pull it off nicely, but I was wondering if people who have already done this have any advice for me in terms of organizing the whole thing, so it’s easy to upgrade and follow through during the time you build it.
I was thinking a standard layout, maybe an intro and a first preloader, then a menu that choses sub-sections and each has an intro and outro transition?
Oh, and for seperate sub-sections, do you put the preloaders in the main movie or do you include the preloaders seperately in each of the subsection swfs?