[thelist] CF: Multiple Language Solution Tips?

I've got a commerce solution that needs to be done in multiple languages,
for the moment there are only two, eventually, it might be as high as 6 to
9. My preference is to generalize it as much as is possible.

Most of the work is to ensure that instructions, form labels, Javascript
error messages  and product descriptions are multilingual. (Obviously, only
one language at time will be used)

Do you have any good tips, or urls or pointers that you might care to share?