The following from an email alert. It should be possible to sign up for these alerts somewhere on the web site.
Live coverage is normally pretty good, starting 20mins before lift off.....
THE ARIANE 5 "ES" LAUNCHER LIFT-OFF for this flight is scheduled during the night of March 8 to 9, 2008 at exactly:
UTC: 4:03 am on March 9, 2008.
PARIS: 5:03 am on March 9, 2008.
KOUROU: 1:03 am on March 9, 2008.
MOSCOW: 7:03 am on March 9, 2008.
Follow the launch live on the internet: http://www.videocorner.tv/index.php?langue=en