You can add many courses to a single course group at one time from Configure | Course Groups. This is a great way to setup online registration when you want to assign courses to a group for the Public Portal or when you want to handle reporting and/or setup and need to assign many courses to a course group for reporting.
Click Configure | Course Groups. On right side of screen, select a course group. Then add courses to this group by clicking the "+" sign. When done assigning the courses, click Save button under Course Group.
** If the Course Group should appear on the Public Portal, you can also select or de-select the "Show Online" checkbox.
The other way to assign course(s) to course groups is one at a time from Course Detail (Find | Courses). At the top of Course Detail, you can assign the course to a course group, one course group at a time.
For more information on course groups, see: Working with Course Groups