Well if you want to spend all that time preparing lessons, some of which you may never use even if you stay on supply for years (by which time they'll be outdated anyway). To be honest i have little prepared in the way of prepared lessons as I found the chances of being in the same year group doing the same unit of work so unlikely I gave up. I try to get to any school nice and early. I quickly scan the classroom for clues as to waht children are currently learning. Quick scan thorugh their books and decide what to do based on that. If lessons are left, which is often the case, one needs little in the way of resources (or has them at home anyway). This, I find, fits in better with their usual learning-just have to think quickly on one's feet. But you've got "a temporary 1 term contract that I've recently finished" so you've more experience than you think. Believe in yourself.