I have just installed Microsoft SQL Express from here: http://www.microsoft.com/Sqlserver/2005/en/us/express-down.aspx
I need it because an example of some code I have uses it.
How do I start using it? Which port does it open by default? All I have after installing it is this:

I'm not asking for a full tutorial on how to admin MSSQL, just a hint on what to do next.
I have downloaded and tested in the past Oracle XE and test it with SQuirreL SQL client with out problems.