Thanks Helen, I need all the photography tips I can get. I don't really understand the 180 dpi thing, though. My camera is a complete mystery to me.
Once, I went through my instruction book and tried to get my camera adjusted to what looked like the best setting for jewelry photos, and I've been afraid to touch it since ... 
the dpi thing is dots per inch - generally the more dots you have, the better quality photo you have.
and/or the larger you enlarge it. dots are essentially pixels that make up the picture on the screen of our computers.
You need to set the camera at a higher dpi setting in order to be able to make an image larger than say it's original size - or if you have a scanner, you could try scanning it at 300dpi - also depends on the megapixels your camera has as to how large you can go.
When you enlarge an image with a low pixel count, it will be displayed as a mosiac. If an image has a high pixel count, the file size will be larger and the card will hold fewer pictures, but the picture can be made larger.
Settings on cameras are sually something like low compression, high compresson, 1/4, high compressoin 1/8, high compression 1/12.
Low compression usually gives the clearest image so if you want to reproduce a picutre for the best quality this would be the best setting and it may read as an
SHQ setting while the higher compression is an HQ setting.