From the Artstor Welcome Page, you can Browse or Search collections.
Browse by Collection:
To browse a collection, choose from the collection categories listed under the Browse menu on the upper left of the Artstor home page. You can select a collection from the list under each category. Click on a collection to browse images.
About the Collection:
The Artstor Digital Library features a wide range of multidisciplinary content from some of the world’s top museums, artists, libraries, scholars, and photo archives, including rare collections not accessible anywhere else. New contributions are added regularly..
Browse across Multiple Collections:
For Artstor Digital Library collections, you can also switch browsing mode to browse across collections by Classification or Geography. For example, you could browse by Photographs: subdivision Indonesia, or conversely, browse by Indonesia: subdivision Photographs. (The Humanities and Social Sciences classification relates to material culture objects and the like. The Maps, Chart and Graphs classification is a good one to remember for historical geography.)
More on browsing Artstor (from the Artstor Support site)
You can search Artstor using keywords or advanced features.
Keyword Search:
The following is excerpted from Artstor supporti:
Please note: Keyword Search will return results that include all of your search terms, so there is no need to include “and” between terms.
You can search across all collections or select a specific collection from the pull-down menu.
Wildcard & Truncation Symbols:
More on searching Artstor (from the Artstor Support site)
Advanced Search:
The following is excerpted from the Artstor support site:
In this interface, you can narrow your search to a collection type, object classification or geographic area (continents and countries).
You can narrow your search by date or a date range.
Using the drop-down menus in the top left of the Advanced Search interface, you can search for terms in any field of the object record, or exclusively in the title, creator or any other specified field. Choose Boolean operators (AND/OR/NOT) from the drop-down menus to the left of the search boxes.
You can enter multiple words in each search box. As in the Basic Search, AND is the default Boolean operator.
Sample Searches:
More on searching Artstor (from the Artstor Support site)