Personally I believe that every body would benefit from regular massage but how often should you book in?
I advise my clients about what massage schedule I feel they would benefit from. I'll give my honest opinion based on what I find during the treatment. However I always try to caveat this with you must set your own schedule based on what you feel most comfortable with. This takes into a number of factors - in particular your own resources. Your time, your money, your priorities, other modalities you are working with. You must take these all into account.
The important thing is that you are comfortable in what you decide.
You may prefer to schedule your massage treatments in advance. Weekly, fortnightly, monthly. Or you may find in easier to book ad-hoc depending on your schedule. Booking in with at least a weeks notice would be ideal, but if that's not possible it's always worth getting in touch to see if a last minute appointment is available.
Remember that massage has a cumulative effect so however you choose to schedule your treatments your mind, body and soul will benefit from regular treatments.