Some schools offer a catechumenal process to prepare young people for reception of the sacraments of initiation: Baptism, Confirmation or Eucharist. This site could be very helpful.
For classes looking at Church History, Sheffield University has prepared a fine site on the famous Cistercian foundations in Yorkshire, England. It includes an introduction to Cistercian life as well as multimedia explorations of five famous sites.
The Santa Clara University Ethics Centre site contains a good introduction to ethical decision making and is well worth a look.
If you are looking for some art to introduce or illustrate scripture studies, Textweek's Art Index could help, or try Biblical Art on the WWW which is also indexed by subject and artist.