Old photographs generally fall into two categories, though the restoration problems you encounter will be very similar.
The first step taken for photo restoration is the successful copying of the original into a digital format. Using a stand-alone scanner, or as is more common nowadays, a multifunction printer, it is relatively straightforward to scan a suitable copy to work on. In this day and age, if photo restoration of any sort is going to be done, you will need a top-notch program to achieve success. Photoshop is one such program that most photographers have and use.