Raid,
You've probably already saved your photo by now, but as a general note to those who have not made the same mistakes as I have...
If you have gone to the trouble to scan in an image, protect that image. First save the image. Then use the "save as" or "save a copy" . This way you with have the original file to go back to if you need to, and you are working on a copy.
So with your file you would first save your tiff. Next, do a "save as" -- naming it something like "imagename-working.psd". Then convert this new file, "imagename-working.psd", to an 8 bit file, and then saving the file as a jpeg ("imagename-working.jpg").
Take care,
Michael