Entering grades into a gradebook should be easy. Moodle helps you by allowing the user to sort students by name four different ways.
After clicking on "Grades" in the administration menu you will be taken to the "Grader Report". Here you need to focus your attention on the header, "First Name/ Last Name"
Clicking on "First Name" will sort your students by their first name in alphabetical order.
Click "First name" again and students will be sorted in reverse alphabetical order.
Click "Last name" and students will be sorted in alphabetical order by last name. 
