You can edit your cron runs over SSH as user with proper permissions if you type ine
crontab -eThere you will have a file where you edit your cron runs. You will find here details explanations what is what. But for drupal setup you should put this line if you wish to run cron every 10 minutes
*/10 * * * * cd /srv/www/yoursite/public_html/; php -q cron.php
There are also some good advanced cron modules, very advanced is
http://drupal.org/project/ultimate_cron
and little more basic but also cool as it makes it possible to run cron without the above crontab http://drupal.org/project/croninfinite