Our school has a sub plan organizational structure that I like. We have 3 folders - each a different color. In the "red" folder, we fill out basic information about our schedules, classroom policies, and our classes. The person in charge of substitutes in our school keeps the "red" folder and gives it to the sub along with a badge and a key to our rooms.
We have a "green" folder for emergency sub plans - it is kept in our teacher mailbox. In that folder I put a set of class rolls and seating charts. I have a list of textbook pages and workbook pages that could be used in an emergency for review. Again ... this folder is for emergencies only. (We have a class set of textbooks and workbooks that we use on rare occasions in our regular classes.) I provide subs an idea of how to conduct a traditional class using those materials (Emergency Substitute Lesson Plans) and provide a list of puzzle problems as well for fun that I found on this website: http://www.eklhad.net/funmath.html.
I also like to use self checking puzzles when I can. So I keep a few puzzles from Algebra with Pizzazz on hand for subs. We have a limit on copies at our school, so I have to be choosy about which puzzles to copy and how we might use them. Algebra with Pizzazz is an old book. I was surprised to find a copy of the book online, as well as the Pre-Algebra version. Then I found the authors of those books have created a new set of books - which you can find at this site.
Last we have a yellow folder kept at our desks for plans for subs that we have time to plan. I try to choose routine practice that students can work on in pairs. After having played "Risk Your Algebra Skills" in class this past week, I'm thinking that would be a great game for a sub. Students get plenty of routine practice and they have fun determining the level of their confidence in their work! Here is a copy of Risk Your Algebra Skills Inequalities that I used this week.
I look forward to seeing ideas that others use with subs!