Cron Set Up

This really is all I need doing. I have recently transferred a website to a new host and the site is working fine with the exception that I cannot set up the cron jobs that I need to trigger the importing of a number of feeds which post on the site. The script I am running is pligg which you can get help from the forum at [login to view URL] and the hosting I use is a vps at westhost. The task has beaten me and I don't know if there is some problem with the script or something else. I have some error messages I can show you which seems to infer that the server is fine. If you need more information then let me know. I want someone to set up the cron (actually three at different time intervals) or at least tell me why the thing won't work and what has to be done to rectify.