For the copyright office registration you don't need a copyright notice on the images, so that should save you some energy right there. Then, all you need to send them is an image that is big enough to recognize on the screen. I send 2000x1500 files, at approx 1.5mb, of digital photos of filled slide pages. That means I'm getting 20 slides copied in one frame, and that's a lot of images overall. If I register digial images, or scans of slides, depending on how much room I have on the CD (based on how many frames I'm registering) I may re-size them down to something like 300 pixels on the long side, and I use an automated method to do it (I use Thumbs Plus, but you can also do it with PS actions). You could also make PS "Contact Sheets" and save them as files. Whatever you want. Its just for registration, not reproduction. Using this method, you can get thousands and thousands of images registered at one time for $30. I suggest though, and what I do is, organize them into logical groups, perhaps by shoot date, or model name, or something that makes sense to you, and put them in folders. I also add a text file called "readme.txt" with a copyright notice, my contact information, and the title of the CD. Remember when you register your copyright, each registration needs a title of some sort. For example when I register every 3 months, I may title one "3rd Qtr 2003". You just have to make it possible for the Copyright office to find them when you need them.
If they are all unpublished (the easiest way to do it) then you can use the one-sided short form, VAS. Be sure to include the check and CD, and keep a copy of the CD for your own records.
Andy Pearlman Studio