try disable your firewall, then connect if the problem persists try to verify you game catch file by right clicking on your css in steam and going to properties then to the local files tab then click on verify integrity of game catch
i hopw this works for you.
it could also be possible that your anti-virus program is reacting to the connection with steam servers
so maybe try disable that for a while
also if you are using vista or windows 7 try disabeling User account controls it dosnt get allong with steam
somthing is blocking steam vac scans thats y you time out
Goodluck