I am currently looking into accepting cc and have been doing a lot of reseach. I will say this first. If you do NOT pay your taxes do not even think about processing cc payments.
1.) DO NOT USE PAYPAL.COM. They are not adult-friendly at all.
Alertpay.com is escort friendly but they take a good percentage and so is Ibill.com.
Geishadiaries.com had a wonderful article about accepting cc. You might want to check that out.
2.) When deciding on what company to go with ask about their chargeback policy. Such accounts are also considered high risk. Ask if they take care of the chargebacks (Alertpay does) or if they penalize you.
3.) When accepting such transactions you want to make sure that your business name ( the name that will show up on his credit card statement) is something generic like GG solutions, GG llc, GG enterprises. This is to protect both you and your client. You do not want his wife to open his statement and see Juggling Gipsy or Busty Betty llc haaaa!
There are a few things you'll want to get before accepting cc. You might want to get a DBA first... just sayin'.
If I think of something else .. I'll add.