re: 5 months away from graduating w/ an MA - When should I start applying for jobs?

You should already be applying. The earlier you start the more you learn about yourself and job availability (work on resume and read over job openings). My wife wrapped up her MBA recently and started working part-time for a firm with about 4 months left of school. That part-time job grew into a full-time position. If that did not work out, I don't know if she could have had a job immediately lined up after she completed her school work. She spent a considerable amount of time on the school's career website which can be very helpful to most students.