If you are creating a portfolio site, one important ingredient will likely be an image gallery to show off your work. It is important with whatever kind of gallery you have that it is easy to update with new content. As such most tutorials on this topic suggest using image files that live external to your flash file, and use an XML file, database, or other such means of telling flash where the images live. This way when you want to put up a new image you don’t have to re-publish your flash file each time.
Image Gallery Resources:
18 AS3 Image Gallery Tutorials
Simple Actionscript 3 XML Gallery
Polaroid Gallery w/ Flickr Integration