Verified answer

Simply go File>Export and from the drop down list at the bottom of the dialog box choose the type of file you want to save it is. You can't save it directly as a PSD file, you need to save it as a jpeg first and them import it into Photoshop and save it as a PSD. However if you're getting it printed and it contains fonts (type) or other vector (smooth edged) artwork save export it to a PDF instead using the Press Quality setting, you will get a much higher print.

If you go to... File ..Save as does it come up at the bottom of the dialogue box?