cron jobs & application removal

[Bob Hemus]

Time to display my ignorance, again.  I looked in man pagesm and 
HOW-TOs couldn't find anything.  I've installed f-prot and 
SpamAssassin.  Haven't screwed up the courage to configure Spam A.., 
but th f-prot sends up-dates and tells me to run them using a cron 
job.  Here are the 'structions:

UNIX users:
Use the check-updates.pl script (e.g, as a cron job) to
update the virus signature files through the Internet.

Would some one show me how or point me in the right direction.  Maybe 
you can teach old dogs new tricks? Thank you in advance.
Bob