Under the Role Groups heading on the left click the icon
Under the Add Role Group heading on the right specify the role group name
On the Permissions tab you can control menu level permissions by clicking on the bar next to the menu name. You will be able to configure 'No Permission', 'Read Only', 'Full Permission' and 'Unrestricted'
To control permissions at a screen level set the higher level menu permission to 'Unrestricted' and select a screen beneath the higher level menu item. From here check or uncheck the Read, Update, Create or Delete permissions as needed
Click Save when you have finished configuring permissions for the role group