Clicking on the database name, the screen for this database looks like:
There are five data sets listed - 1885 to 1916, 1917-1938, 1939-1942, 1943-1946, and 1947-1951.
It is important to note that this database contains images of the index of marriages by surname, not a database with images of actual marriage licenses.
Between 1885 and 1938, the marriages in this index are listed alphabetically by surname, and then alphabetically by given name. The spouse's surname is listed in parentheses, and the marriage license number is listed. The screen below shows the selection screen for the 1885 to 1916 database - I was looking for "Seaver" in this index so I scrolled down to the S data set.
I clicked on the first part of S, and found that there were 300 pages in this data set. Page 1 is shown below:
The user has two choices to find a specific surname in this database - either page through it one page at a time, or guess at a page number and enter it in the "Goto" box in the upper right corner of the search page. I chose the latter, method, and quickly found page 158 with Seaver on it, as shown below:
The format of the 1939 to 1951 databases are somewhat different. They are handwritten in columns for males on the left-hand side of the page, and females on the right-hand side of the page. The data sets are still separated by the first letter of the surname, but within each data set they are not arranged alphabetically. They are listed semi-alphabetically by given name - all A given names are together, then B, etc., and grouped by month and year! Again, the spouse's surname is given in parentheses, and the Marriage license number is provided.
The screen below shows the screen for the 1939 to 1942 database. I was looking for a specific person, John Robinson Hall, so I chose the H listings.
The first page of the H listings show that this list starts with the given name of A - Abraham Harris for the males on the left and Augusta Harper for the females on the right, as shown below.
At this time, the 1947 to 1951 marriage index pages are not available on the web site.
If you find a marriage index record for your ancestor, then you need to write down the marriage license number. The Historical Society of Pennsylvania web site provides information for obtaining marriage (and other vital) records in Philadelphia at http://www.hsp.org/default.aspx?id=128. For marriages between 1884 and 1938, the actual marriage licenses can be observed (and copied) from the LDS Family History Library Catalog in the Microfilm 0,972,956.
Unfortunately, I didn't find John Robinson Hall in the 1917 to 1946 indexes. My colleague will be disappointed, but not surprised!