Various suggestions to get the attention of the whole class to prepare them for various other activities or to get them quiet. Some may be more appropriate for younger students, while others work better for older students.
This is a site about class management in classrooms with examples varying from procedures, signals, pets, and games that help the class function productively.
This would be useful for teachers because it gives many resources for specifically elementary school teachers. Also, this website has videos and links for what are good assignments and ideas to bring forth in classrooms.