g1smd - 2:48 pm on Jan 4, 2013 (gmt 0)
You'll need to choose what type of bar code is printed.
There's various sizes, with narrow or wider bands, and various digit lengths.
There's an international numbering scheme which you will need to conform to, though if the code are only used in-house there are shorter (less digits) number ranges for that (you'll see them on "own-brand" products in shops).
There are various numbering conventions, UPC, EAN and others, typically: 2 digits for country code, 5 digits for maker, 5 digits for item, and a checksum digit.
Of course, with room for 100 country codes, 100 000 companies per country and 100 000 products per company the system design was massively under-specified.
Pick the wrong system and you'll find some readers can't read them.
Instead of barcodes, would this be a use for QR codes?