From within the course to which you want to add new users, go to the Administration Block and click Users.
From the expanded Users menu, click Enrolled Users.
You will be taken to a list of all the users currently enrolled in the course. Click the Enrolled Users button.
In the window that appears, type the name of the user you want to add in the box at the bottom of the window and click Search.
Select the role you want them to have from the Assign Roles drop-down menu: Student will add the user with the same capabilities as students have. Course Builder will add the user with the ability to add, remove, and change course content. Course Builders do not have access to grades.
Click the Enroll button next to the user you want to add. The window will stay open, and you can continue to add multiple users this way.