Originally Posted by superwookie
As far as how you show your client-- well, that's really up to you. Some people will crop the final design and save it as a .JPEG, but I would imagine a .PDF is fine. I find that people in general understand images better, so I usually just send two images (one front, one back) to my customers for review.
As far as format for printing, your best bet is to contact your print shop and find out what works best for them. A simple phone call should be all you need to get their preferred file and size specifications.
I would print out the image at actual size on card stock, cut it to actual size, and show that to the client. Don't show him anything else unless the client wants all the files to handle printing himself.
As written above, absolutely contact the print shop to make sure you create the files with crop marks, etc. exactly as the printer needs them. It's possible you are using an online print service, so that all you need to do is look up their specs and upload the JPG (which would be in RGB, not CMYK).