Once you have invited students to your class and have a lesson assigned to the class, you can view your student's progress from the Grade Book tab in the teacher dashboard.
If you click on the course progress percentage, you'll see a small window popup with some additional details such as how long the student spent on each step of the lesson.
Once students have taken the quizzes that are assigned, you can click on the grade percentage in the Grade Book to pop up a window to view their responses and do any grading needed for short answer responses.
If extra grading is needed, simply click on the "Grade Essays" link:
After you click on the Grade Essays link, the student's short answer question responses will show up for you with the ability for you to enter a point value that you feel the student earned, as well as leave feedback for the student:
When you're done grading you will see the updated grade for the quiz, and have the option to email the grade report to the student or move on to the next report to grade.