There are two ways to search the archive. You can browse or you can have a directed search. If you browse the archive, you can just page through the entire archive. Alternatively we have defined various "tags" on the pictures. These tags can be used to look at a set of pictures that all have the same tag. More information can be found on the Browsing help page.
The other method is to use a directed search. The directed search allows you to specify various fields to review and values for those fields. Some of the additional help pages specify the fields and the types of values you will find in those fields. More information can be found on the Search help page.