How to schedule jobs with Cron

/etc/cron.d/yourcronfile

MAILTO="root"

# minute (0-59)
# hour (0-23)
# day of month (1-31)
# month (1-12)
# day of week (0-7)
# [minute] [hour] [day of month] [month] [day of week] [command to run]

0 * * * * root /usr/local/sbin/yourscript > /dev/null 2>&1

For example, to run a command every minute:

/etc/cron.d/every_minute

MAILTO="root"

# minute (0-59)
# hour (0-23)
# day of month (1-31)
# month (1-12)
# day of week (0-7)
# [minute] [hour] [day of month] [month] [day of week] [command to run]

* * * * * root /usr/local/sbin/yourscript > /dev/null 2>&1