A major part of early childhood education (and yes, 3rd grade is still considered "early childhood") is teaching social skills and responsibility. I gave a lot of thought to how to change my "classroom jobs" to fit the students I will be teaching this year. In years past, I just gave every one a job. They had said job for a week, then it rotated. I wanted to make my 3rd graders more aware of the responsibilities of having a job, as well as giving them ownership of the job they have been given.
What resulted was 12 job descriptions, with 2 slots available at each position. Jobs are for 1 grading period (6 weeks), and students have to fill out an application. I'm sharing my job descriptions here, and the application here.
I am using the Carson Dellosa Sea Life Dimensional Accent pieces seen above, with 2 names written on each card (wipe off marker).