This site is comprehensive and well organized. It features many pages dealing with the cultural and religious background of Paul's life and thought. Maintained as part of the Third Millennium Web site by Prof. Reggie Kidd of Reformed Theological Seminary.
This is a picture guide to the ancient Mediterranean sites that Paul visited on his travels. It does a good job of introducing the basic cultural features of each site.
This is a remarkably comprehensive site that deals with the religion and culture of the apostle Paul, dating the apostle's life, and a very detailed attempt to interpret all of Paul's letters within the context of a chronology. Maintained by Peter Bercovitz of West Virginia Wesleyan.
Footsteps of Paul
(http://www.abrock.com/Greece-Turkey/FootstepsIntro.html)
An illustrated and annotated travelogue from a tour of sites in Turkey and Greece that relate to Paul's missionary journeys.
Although this Web site is geared toward providing informed resources for Christian preachers, the lists of Scripture passages in these tables are linked to rich lists of resources from all around the web. This is an excellent site for finding what relates to a particular Scripture passage