asked the same thing and got this quite good answer: How to track execution time of each line / block of lines / methods in PHP?, beside that i have this answer also on a currently running other question with the same content.
Some additional notes on that (stuff i've collected in other SO posts in my own research with this problem):
The port might be also 9001 (seems to work for some people while 9000 don't).
Switching to PHPStorm IDE is a real alternative that solves this problem (as PHPStorm has included perfectly running xdebug already).
Download a new version of xdebug via the wizard (http://xdebug.org/wizard.php) and if you follow the instructions maybe you will be lucky.
Switching off the firewall might help.
Add to php.ini: xdebug.idekey=netbeans-xdebug.
Find out if you have a xdebug.ini file and add the xdebug related php.ini lines to that file.
you have to un-comment the zend_extension line (i.e. remove the ; at its begninning), so Xdebug is actually loaded.
make sure Xdebug is loaded, calling phpinfo() from a PHP file (just to be sure).