If teaching is to be your part-time job, as it is with most people, you must be sure to have the fundts to teach. You must purchase a set of hornbooks. These are essantial to tach the alphabet and numbers. If you are to be teaching wealthier students, you should be sure your classroom is also equipped with letter bock -- but take good care of these, as they are valuable!
You must also teach your pupils good writing skill. Stock up on inkhorns and goose quills, as the students are to bring their own paper. Stress the importance of not wasting valuable paper.
Expect to teach girls that are the siblings of wealthy boys you may teach. These girls are especially lucky because they shall be learning their regular household arts as well as schooling. See that they do there lessons well, as they will most likely not have any other educational opportunities in their future.
For foreign languages, prepare to teach some children whose parents have already taken them to the countries whose languages you are studying. Be sure you are familiar with these places yourself, as it is you who must be teaching them!
In conclusion, make sure you teach the pupils well. If they go on to apprenticeship without the necessary skills, you will be reported, labelled as a faulty teacher, and will no longer have any business!