Around here it seemed like the job hunt really began after boards (December). Before that people seemed too focused on just passing boards to worry about the next step.
If you're going for the match, the deadline is in December.
We get up to 4 weeks at clinics of our choice and 8 weeks of "vacation". It's in quotes because usually you're working on something and it's not much of a vacation. Some people spend that time trying to make a good impression on a clinic or academic institution they like. It does make a difference. If you can spend a few days at a practice you'll have a better shot at being considered for a job. I had two job offers before they were even publicly advertised.