Planning your lessons is a very important part of teaching, it will help you have a more organized material for your classes.
You should document all your classes and the plans for it, not only will it be helpful for you, but in case of the need for a substitute, if you give him your documented plans for the classes and give also your own comments and thoughts on the subject, it will make it very easy for the proffesor and it will help your students very much because they will not be losing any time.
