Adding A CNAME

I did look at other topics submitted by others but didn’t find info on this question.

Hostgator has a place where I can add a CNAME using the cPanel > Simple DNS Zone Editor or the Advanced DNS Zone Editor.

My All-In-One book for Dummies tells me I should add a CNAME record with the value of *.CNAME. Is that the exact text I enter or am I suppose to replace the CNAME part with a domain_name.com or subdomain_name.domain_name.com record?

Thanks for your help,
Jim