Need Help With Setting JPEG Compression

I am scanning some small pictures that I am going to e-mail someone else to make me 4×6 prints out of. They e-mailed me back and said I needed to set the JPEG compression to the highest quality setting possible. Could someone please tell me how to do that? I do not even know what that is? I am using a Epson Stylus CX3200 all in one, and have Windows XP Home Edition on my system. Thanks for anyone that will e-mail me back (EFCloggers@aol.com) and let me know how to do this. Thanks again!!!