If you want to convert  a box of paper photos to digital images it's easy enough with a scanner or mobile phone camera- but if you want to add any text about the image without writing on top of it you'll need some dedicated software.

Caption Pro can add 2-part editable captions to your digital images and interface to a scanner with an auto-crop interface which lets you extract individual photo images. It can also create a PDF file from multiple images - ideal for creating digital facsimiles of diaries or sequences of letters. It's available for PCs and Macs and there is a free web captioning facility too.