Should I prepare anything?
You can of course get clean and make some time for and after the massage (20-30min), and:
Bring a large towel.
Current context / history: This includes recent surgery, chronic ailments and medication, but also anything that you find relevant regarding your own bodily history and context.
Expectations: I assume that you’re doing it for relaxation purposes, but you might be a bit more explicit. Don’t worry if it’s too much - I’d rather have you express yourself than my having to guess.
What should I expect from a massage?
Massage being an end in itself, it can as easily much end up in a long and strenuous rubbing down with oil as in an intense experience of attunement and meditation. It’s usually relaxing, and that’s good enough :).
I can only guarantee you that I’ll do my best to rub oil over you in an orderly fashion, with sincerity, fairness and attention. However, I’m not a magic healer (nor, hopefully, a nonetheless magic charlatan), so please don’t use massage as a replacement for medical treatment.
How naked should I be?
Exactly as much as you feel comfortable with. If you feel shy, or uneasy uncovering some parts of your body, don’t worry about it, and please don’t hesitate to tell me!
Many massage traditions do not require you to remove your clothes at all - and you’re not loosing any of the benefits of massage (except of course for skin oiling).
For an oil massage, you can either remove your clothes fully or keep your underwear. For a massage without oil, the best would be to wear loose, cotton clothes.