As far as UPC codes go, you can use a barcode reader or enter the numbers manually.

And yes, you should include all the numbers.

As far as I know all newer products follow the the EAN-13 format, which means that there should be 13 digits. But you'll probably also come across products which use the 12 digit UPC-A format.

See [url]http://www.ean-int.org/productssolutions/barcodes/technical/bar_code_types.html[/url] for further information about barcode types.