One classroom management strategy is to post rules around the classroom. This serves as a constant reminder for the students. I have created some "posters" for my classroom. You can print it letter size, and take it to places like Office Depot to be enlarged to ledger size (about $1).
I included the pdf file for printing, and the PowerPoint file if you wish to edit the posters.
Here is a sample with 3 posters. Please see my other listing with 12 posters.