What connection string can I use to connect to my MSSQL database?

The following connection string is an example. More connection strings can be found on the ConnectionStrings.com website.

<add name="strDBConnection" connectionString="Server=.\;Database=DBNAME;uid=DBUSERNAME;pwd=DBPASSWORD" />

DBNAME is what you specified as your database name in the control panel (accountname_DBNAME)
DBUSERNAME is the username you created to connect to the database (and was associated with the database in the control panel). (accountname_DBUSERNAME)
DBPASSWORD is the password you associated with the username above