there are several ways you can do this but each of them would require some experience using DNN to start with..
Here are a couple of pointers that should get you started.

a) If your database is another SQL Server database or Oracle, simply add a new connection string in your web.config (in the right connection strings
b) In the code for your module, use the appropriate DNN methods to pull the connection string from web.config (if you want examples, look at the dataproviders for any of the existing modules).
c) Create a command/connection object using your new connection string.
d) write your SQL statement or call your stored procedure using a datareader, etc.
e) bind to your controls...


the key is creating another connection string in web.config and connecting to it via your module..
Sanjay