From the student grade page, you can view the grade distribution of the whole class, as well as specify new grade ranges.
Viewing grades:
By assignment type as defined by your grading scheme:
From here you can look at an individual student's scores by clicking on their name or at their individual submission by clicking on their score.
By clicking on a student's name:
You can reach this page by clicking on a student's name in the course roster as well.