Once you have created email accounts, you can check them through cPanels built in webmail programs. Depending on your hosting package, you have the option of Roundcube, Horde, and SquirrelMail by going to:
http://www.domain.name/webmail
Once you have logged in, you have to choose which webmail client you wish to use. Each one does the same basic function, it is a matter of preference.