You can mass load schedules for students. First of all, you must be able to 'group' the students together, i.e. all students in homeroom 121 will have the same schedule. If not, you can enter a list of student ID's that will have the same schedule.
Make sure that you check the Mass Load Scheduled Courses log on your Tasks and Reports. The log will let you know how many students were scheduled and if there were any errors.