So with that said, when I send my files to kinko's, walmart or some online printing company
- should I be sending them JPG (fine) or RAW? [/*]
- and what pictures sizes can I expect from an 8 MP camera? [/*]
Always shoot RAW. If you convert to TIFF, you will lose nothing. JPEG is a lossy compression that does leave information "on the table". I've not seen a place that couldn't use TIFFs. Most online photofinishers accept only JPEGs, except for this place:
I've used them to get slides (for competitions) from digital. They allow you to upload TIFFs or PSDs in just about any size, so if you want to do some careful upsizing before you send your images, you can do so with you having the control.
I've seen 20D pictures printed to 20x30 by a local photofinisher. They were quite impressive. At captured image size, that is about 115dpi before upsizing. You have to see it to believe it. I personally print 13x19s all the time on my Epson 2200. People can hardly believe the quality from the 17-85mm IS lens on the 20D (and these are people in a camera club!)