I am up making a cake with a elible photo for tomorrow. Do I put photo on tonight? Will it still be alright for cake cutting at noon?

I would go ahead and put it on now. Sometimes after your frosting has crusted, it is hard to get them to stick on the cake. I have never had a problem with putting them on the day before!

Definately now...the longer it sits on the icing, the better chance it will soften up (I have always had trouble with my images being "papery") and blend with the icing.

I have put them on buttercream the day before and not had any problem the next day. The instructions say that you can put them on after the frosting crusts if you want, but you have to spray a fine mist of water on the frosting. I have not tried this but have heard that it works. Myself, I prefer to put it on before the frosting crusts. Hope this helps.