Google Apps is a cloud computing suite of services that includes web-based email, documents, and other services. Unlike standard Gmail, you can use it with your own domain (i.e. instead of firstname.lastname@example.org, you would have email@example.com). To setup your domain to use this service in cPanel, you need to edit three things:
To edit the MX record, go to the Mail section in cPanel and click MX Entry. Enter the records according to Google’s specification, but exclude the period at the end, as it is not needed in cPanel.
To edit the CNAME records, click Simple DNS Zone Editor in the Domains section. If “mail.yourdomain” is already taken, you can choose another name or click Advanced DNS Zone Editor to change it.
Finally, Google recommends setting up an SPF record. This is also found in Advanced DNS Zone Editor. Once you have that setup, you are finished setting up Google for mail service, but the DNS will take some time to propagate.