how to set up cron jobs?

I use CentOS 5.2 + Lighty as my web server without any control panel. I do everything by command lines. I need to run a python program (google sitemap generator) every 24 hours and would like to set up a cron job for it.

I wonder how to set it up? could somebody here help me?

thanks

 

well, I think I've found out how to set up a cron job now. I set up one using this command as root via SSH:

Then I typed in following lines in the crontab file:

I saved the file, waiting for it to run the cron job.

However, after 8:20pm, I didn't see any new sitemap was generated. I think this cron job wasn't working?

So my question here is how to make it work?

thanks!