I have three expectations for all of my students - be responsible, be respectful, and do your best. Those three encompass all rules, expectations, and keys to success. I am able to refer to my big three to address behavior, motivation, and academic issues. It short and simple, and easy for students to understand.
The two posters are originally 24"x36", which in my experience is the typical poster printer size found in schools. It can also be printed on 8.5"x11" paper, or whatever you size you adjust it to on the PDF print settings.
If you would prefer different font or background, send me a message or comment on TPT, and I will help you out. Enjoy!