Hi Yvon,
if you click on the Import icon you'll find several settings on the right hand side of the screen. Be sure to select the desired folder under "Save files in...." In order to rename the files according to a pattern which fullfills your personal requirements select "Rename files" and choose one of the standard renaming patterns or - alternatively - create your own renaming pattern (there's a "customize" entry down in the dropdown list). Also be sure to check the "Rename Originals" option box! Otherwise the names will only be changed in APerture but not in the Finder.
Depending of what you prefer you may either select "Move files" or "Copy files" in the "Save files in.." section of the Import dialogue.
One last tipp: Try the procedure with a few dummy images first before you start with your 20,000+ collection, o.k.? I know that things may be weird if you miss to set the correct options...
I hope that works for you!
Cheers, MIchael
P.S.: As I don't have the English version of Aperture running (or more precisely the English locale on my system) it may be that the lables ofthe respective settings read slightly different.
Message was edited by: d-light