Beware of the Eastern European businessman whose body is covered with prison tattoos. The source of their "first $million" should be obvious.
Finding one's "first nude" is easy. There are only two basic choices:
1. hire a professional, or
2. sweet-talk an amateur who looks promising.
Either way, not having an existing (which comes first, the chicken or the egg) portfolio of work, one needs to convince the model of one's honesty, character and sincerity. Even with a portfolio, the comfort level of the model is essential.
Where to actually locate such a model depends a lot on geography and culture, along with the personality type of the photographer. Here in the U.S., for example, colleges and art schools may be a good place to start. The model first needs to be comfortable with her own body, and second, comfortable with the photographer. Female college students, in general, and those who have modeled for art classes, in particular, are more likely to fit into that category. Random women at the shopping mall are less likely to be so inclined. And, contrary to typical assumptions, cabaret dancers are probably the least likely to be willing to model nude.
My preference has been to hire professional (or, quasi-professional) models who already have experience, a reputation for reliability, and "have a clue" about modeling. I've found that approach to be less expensive overall, and far more productive in terms of quality work.