After carrying out recent studies, supply teachers say that the thing they worry about most (after finding work) is being able to control a class. Often being thrown in to a classroom of children who you have never met before and possibly within a school that you have never taught in before can be very daunting. If you have previously worked in a permanent position in a school, you will have had the opportunity to bond with the class and work out what works best in terms of keeping them interested and keeping a correct level of control. You need to establish ground rules from the first moment the children enter the classroom.
Classroom control is vital to gain the respect of the children and to ensure that works get completed on time and to the correct standard. Without control you may find that disruptive pupils start to affect the while classroom and this can be hard to get back under control. If you have a teaching assistant working with you, then be sure to speak to them about how the class is normally ran and if there are any pupils that you need to be aware of.