Page transitions question

i am trying to make a portfolio-like page… i have all the buttons ready, now all i need is to make the swf’s for the images… i would like it to load, transition in, and transition out… how do i go about doing that? do i put a preloader on the image swf movie or in the main movie? and for the buttons of the main swf, how do i tell the currently playing image swf to transition out, and tell the next image swf to transition in?
any help would be appreciated, simple pseudocode or full blown example.:slight_smile: thanks in advance.