The hobby is a deeply personal experience, unique to each one of our own set of desires. On one hand, he like most of us, has to pinball his way through the myriad of different experiences, some good, some bad. Nevertheless, here are some generic thoughts strictly from my perspective.
First, before he even sees a lady, have him spend some time on the boards here. Reading through posts, reviews, and ads is a good way to get a feel for the experience. Back in the day, there wasn't any such information, and the hobby was definitely hit and miss. Actually more misses than hits. So the both of you are lucky you have a wealth of knowledge available.
Second, have him see a variety of different ladies. Some young, some middle aged (30-39), and definitely, some mature providers (40+). It'll be easier for him to find his niche. He'll also be surprised that a connection can happen with any lady, of any age.
Third is maybe give him some sage advice on how to avoid some of the pitfalls. Like being able to recognize fake pics, fake ads, and fake reviews. How to be patient, and not think with his cock, because rushing is a good way to find trouble. That it's okay to walk away if things don't feel right. Also teach him not to give out any personal information, no matter how good the connection. You know as well as I do, sometimes these ladies, for a variety of different reasons, get a little jealous. Personal info in the hands of the wrong lady is a recipe for disaster.