Not sure where to start with this question. So many potential
directions.

First, it is highly recommended by nearly every major software vendor
that has provided an API to access their database that you NOT query  the
database directly.

Microsoft Windows SharePoint Services Web Services are another way to
access List data. Take a look at the Lists.asmx Web Service for
starters.

SQL Server Reporting Services SP2 also has some Web Parts that may be
helpful to you.

Don't overlook the power of the ListView. Slicing and dicing data  is
quite compelling when delivered in a ListView.