Depending on the district there may be a dress code you need to follow. I would suggest business casual to be safe if you aren't sure.

Depending on the school and the district would depend on what the dress code is. Normally, for the first couple of times of being a substitute teacher, you want to look professional. Some other times when you get used to it and have more experience, then jeans without rips and a blouse would be just fine.

I am in the same situation. I am a sub three or four days a week while I am earning my teaching degree. I always dress buisness causal. Something that is professional but is comfortable. Clothes that cover everything and are not too form fitting.