Chronjob help?

Another plea for help from my readership:

I’m trying to use this WordPress hack to import my del.icio.us bookmarks in WP: YADD.

I’m having trouble figuring out how to setup the chronjob right. If anyone could help me out, or at least point me to a relevant guide to setting up chronjobs, that’d be great (my googlefoo is failing… I haven’t found a relevant chronjob guide yet).