How often you record depends entirely on the nature of your podcast and the schedule of the people involved. Some people record weekly, bi-weekly, monthly, or only a few times a year.
You might record all of your podcast episodes over one month, then stagger the release dates over a year. As long as you have a regular schedule so your listeners will know what to expect, you can choose the frequency at which your podcasts are released. However, if you wait too long in between episodes, people may lose interest.