The required textbooks for the class are both available online:

Internet Application Workbook
SQL for Web Nerds

If you are using the Oracle RDBMS, we strongly urge you to purchase:

Amazon logo Loney, K., and G. Koch.Oracle9i: The Complete Reference. McGraw-Hill Osborne, 2002. ISBN: 0-07-222707-9 (or an updated version if available).

The official Oracle RDBMS documentation is available (registration free but required). We particularly recommend the Application Developer's Guide. However, the rest of the Oracle docs are often too detailed for beginners, which is why the Oracle9i: The Complete Reference is so useful. We also recommend:

Amazon logo Tufte, E. Visual Explanations: Images and Quantities, Evidence and Narrative. Graphics Press, 1997, ISBN: 0-9613921-2-6.