Like the above poster said in the last paragraph, image degradation happens when you edit the image and re-save as a jpeg. What happens is that data is compressed when creating the file, then you compress it again every time you save it again. When you save as a TIFF, you lose nothing (but your file size is huge). But transferring the images to the computer, then burning them to a CD won't degrade the files - as long as you don't edit and re-save the files.

So what do you do if you want to edit a file? In most cases, you could edit the image that was shot as a jpeg, save it again (select the least amount of compression or highest quality level here) and be fine even with a print. You could even save it a couple of times this way and it would be unlikely that you'd have a problem. If you want to see what happens, bring up a fairly detailed image in photoshop. Save it as a copy (so you don't lose the original!) with a low quality. Save it again several times. Eventually you'll see that you're losing detail. Keep going and it will just get worse. But it will take a few saves before you start seeing it.

Something that's a portfolio piece or a big print - an important image - I'd handle differently. Edit the original jpeg file. Save as a TIFF as you're working on it, and keep the master copy this way. Then save a copy of this TIFF as a high-quality jpeg to bring to the lab for printing.