You should also include the edition information if it is a limited edition print, but under the bottom-left edge of the print.
But something that people can actually see (a signature) is much more easier to remember.
Signing your work is, first and foremost, a mark of a professional artist (or an artist who intends to be a professional).
But the other major benefit to signing your prints is that it helps you to lay claim to your art and can sometimes settle copyright disputes.
You can also try leaving a question - see comments - and I'll try to point you to where you can find the answer If you only sign one panel of a diptych or triptych what happens if the painting gets split up either accidentally or on purpose. The safest thing to do if creating your own diptych or triptych is to make sure every single panel is marked with your name even if you only sign one on the surface of the painting.
You could choose to only sign one panel on the front of the painting with your signature - to indicate this piece of art is one piece as opposed to two or three.