The purpose of the interactive notebook is to enable students to be creative, independent thinkers and writers.
Interactive notebooks are used for class notes as well as for other activities where the student will be asked to express his/her own ideas and process the information presented in class.
Requirements vary from teacher to teacher and is set up according to the directions of the teacher. Some go left/right, others go right/left, and still others go sequential.
It really does not matter, so keep that in mind when looking at the suggestions.