What folder structure for multiple product images does VM 2 expect?

[webist]

I will soon be bringing a 4000+ image database in to VM for a redesigned web site which will newly feature e-commerce. My present site has images in a main image folder with sub folders for different manufacturers. I maintain the site by using an ftp mirror of the image folder on my workstation and maintenance is fairly intuitive as I can examine particular folders knowing what they are if there are any problems. I'm wondering what expectations VM 2 has regarding image folder structure. Do I need to place all images for a given SKU in one folder? Do image folders need to be named in a particular way or can I use a scheme similar to my present site? Just trying to get an idea of what changes in my workflow and maintenance implementing VM 2 will bring. Also, where can I find any documentation on this subject? Thanks for any info on this.