I love historical photographs, they tell me so much more than words. A lot of elderly people have wonderful New Zealand history stashed away in their cupboards. I've come across two collections so far and was able to persuade the owners to let me scan them.
I took a laptop and a scanner (they are so light these days), to one relative's house and scanned the lot, while she chatted to me about who was in them. This I noted on word as I went, numbering the comments and the photos which were done in batches. It took all afternoon. The other was an album mailed to me already annotated.
The owners received a dvd of the photos, saved as tiff files to preserve all the information available. These can be cleaned up with photoshop later if need be. I've been told recently that png files would be better. Png stores less information, but is lossless like tiff.
A little digital camera with a good macro facility such as you may take to the archives is a good idea when visiting. If you have a steady hand, you can get a shot almost as good as a scan. I have used a tripod sometimes or a special stand for the camera. Lighting is important but don't use the flash. Here is an example of a pretty lass from one of the albums.