I disagree about a picture being "worthless" without the journaling. I'm currently working on photographs from 1904-1930. Pictures that have been loose in a -- oh, dread -- shoebox and taken out to be simply thumbed through year after year. No dates, no names. But yet, they have remained family treasures. The only thing really known about the pictures are the family members depicted.
Don't get me wrong, I'm not advocating for not journaling. If someone had taken the time to write simple dates, places, and names on the backs of the photos it'd've been a terrific help in my project. As it is I use a magnifying glass and try to determine through the photographic clues which pictures go together. Yes, journal indeed. But don't feel guilty if you can't journal everything, but never leave out the basics.
And, yes, before you even ask, I am leaving space for journaling, as when I share the book with other family members, and perhaps even my 99 and a half great-grandmother -- with these newly enlarged photos that show such detail that had been lost before -- perhaps some stories will come out which I can include. At least that's my hope. Some stories may have been lost forever, but the feelings are depicted through the expressions and images.