Editioning
You may find these links helpful when editioning your prints:
http://makingamark.blogspot.ca/2011/10/how-to-sign-art-print.html
http://inkmasterscairnsinc.ning.com/profiles/blogs/how-do-i-sign-a-print-what-is-an-edition-prints-and-printmaking
Do keep in mind that there is tradition that some like to follow but also wiggle room as rules change, contemporary practices differ... and it's your artwork!