"Server=.;Database=sladesfaculty;User ID=username;Password=password"

^ Should work fine. Also, you need to make sure your SQL Server is set for SQL Server Authentication (and not just Windows Authentication). Just because you've made SQL Server Authentication usernames and passwords doesn't mean its set properly.

In SQL Server Enterprise Manager, right click on your server, and go to properties. On the "Security" tab, make sure the "SQL Server and Windows" radio button is selected.

FYI, the "." is a shortcut for localhost in an SQL Server connection string .