First, you should get familiar with course properties as they pertain to Group mode. If you click Settings on the course homepage you will bring up the properties window. The Group mode property allows you to make one of three selections for how Groups will behave. In my illustration I have selected "Separate groups" and enabled Force so that the feature is active within the course.
Next, you will want to to click the Group icon on the course homepage to establish members for each group you will define. Unless you have clicked the "Turn editing on" button, you will not see anything when you enter the Group setup window. When you have done this, you will see a list of all users that are enrolled in the course in the left column, teachers and students alike. Groups does not care what status a user has. There are three columns:
- People not in a group
- Members of selected group
In the center column (Groups) you have an option to "Add new group" names. Do this for whatever groups you wish to create (e.g., Tutor Jones, Tutor Smith etc.). Next, simply assign each user to a particular group, INCLUDING the tutor, displayed in the left column by first highlighting the group you have created and then using the "Add selected to group" button. Experiment with this, you really cannot screw up anything as you add/delete in your practice setup.
A few things to consider: When you add teacher/tutors to a course by clicking the "Teacher" (or whatever name assigned in course properties) link in the Administration panel on the course homepage, you have an option when making a user a teacher as to whether they will have "Editing" permissions. Generally, the teacher who is the course creator is the only user who should be given Editing permissions. These permissions allow the teacher to alter the course itself, something that will effect all groups. Therefore, assign this permission with oversite. Finally, although isolated in their own group, tutors are able to view certain activities (Forums etc.) in other groups if they wish (birds-eye view). This will become evident as you explore the feature and determine what settings will work for you.
Hope this has been helpful.