I am fortunate to have this photograph from my great-grandparents' wedding that my father gave me shortly after my own wedding. Although I am accustomed to finding a document and never finding a visual representation of the event, in this case, I have no documentation or any idea where and when they were married. While beginning my research on their marriage, I have been considering potential sources of information that could help me.
Depending when and where your ancestor was married, they may have left the civil records we most often think of--the marriage license and marriage certificate. However, there may be other sources recording this event, which can be beneficial to our research--church records, newspapers, Bible records, and invitations.
The couple may be presented with a marriage certificate unique to the church, which could hold information other than what appears on the civil certificate. For example, I have seen such certificates that contain the names and home addresses of the maid of honor and best man. This could be interesting, and potentially helpful in your research, to know if these individuals were relatives or neighbors of the couple.
Also, newspapers are used to announce engagements and marriages and may contain more personal information on the couple, such as where they plan to live after the wedding, who was in attendance, and a description of the dress and reception festivities. In the absence of a photograph, a first-hand account can be an exciting find. I came across one such article on a different couple, which described the bride's dress and even named out-of-town relatives they were to visit after the wedding.
Finally, Bible entries, or a Bible presented to the couple at their wedding, may also provide details about the wedding and the family, such as the date, location, and the bride's maiden name. You may even be lucky enough to find a wedding invitation, which could provide as much information as any of the other sources, such as a maiden name, parents' names, and locations of the families and ceremony.
Their story may be been forgotten over the years, but seeing my ancestors' faces gives me motivation to seek out these sources in an attempt to piece it together.