You might want to wait until the chemistry is going and then ask if certain acts are OK. If you are interested in anal, that often has to be prepared for ahead of time. That should be spelled out in her profile.
I would wait until you became established to ask too many questions. If the gal is well reviewed, what more do you need to know?
Show up on time and be clean with fresh breath.
Don't get hung up on the details and try to keep pre meeting communication to a minimum unless the girl initiates it. IME there is a lot more chance for something to go wrong than right with emails/ pms etc before hand.
Just show up with an open mind and let her show you what she can do, that always works for me anyhow. If there really is a question you need to ask beforehand just make sure that info isn't available on her website. But I think most things can wait until you meet face to face.
I find it's best to build up a little chemistery before making requests for specific acts. Asking about specific sex acts before you meet the first time will often get you ignored, clothing requests or something like that is usually fine.
...get it. $30 for VIP is dirt cheap compared to the cost of a messed up session. With that membership you can read the reviews of these ladies and have a better idea of what can be expected in way of activities. Their web site can give you a good idea but the profile & review here really fill in the picture.
I know you said they are well reviewed. I hope that means well reviewed here on TER and you have checked them out thoroughly. I say that because some have said a provider was well reviewed later to reveal she had two reviews by gents with one review to their credit but the numbers looked good. That is not well reviewed.
The previous posters gave good advice. Discussing activities before the session is not recommended. Wait 'til you are there and go with the flow. By the reviews you read you can know what's available and inquire if you need to as things progress.
if it's a generic type question, than to embarrass yourself and maybe her in person. You might catch a little crap if it truly is dumb or easily found info, but that's far better than looking like a fool. I should know, lol
Thanks for the feedback everyone! Yes, I did get the VIP to do my research. One lady has just under 20 reviews, but looking at those that reviewed her shows that those gentlemen have reviewed what appears to be many reputable providers. For a newbie, that looks good to me. Thanks again.
If you mean on the phone while you are booking, the answer is "no". Never discuss specific sexual acts.
If you have preferences as far as outfits, or a fetish that is not specifically sexual, then it is usually fine to bring up. But always be cautious with the wording, and also keep in mind that many women will get spooked if you ask too many questions, even if they are not overtly sexual.
If you are talking about once you are in the room and the business has been taken care of, then you can ask her anything you want. But if you are talking about something like CIM, for instance, just think about it. If you ask her, on a first date, before any action has begun, then a lot of girls might say "no" just because they don't know what your dick tastes like yet, and don't want to commit; if you ask during the blow job she's more likely to say yes if everything is going well otherwise. I'm just speculating here.
I guess I'm saying that letting "chemistry take it's course" might result in you missing some specific thing that you wanted, but on the whole the session will probably go smoother; asking for specific acts in advance MIGHT get you those things that you want, but might also result in a more "wooden" and less sexy session.
I can't remember discussing sexual acts with a provider, before, during, after, ever. It just doesn't come up. The girl usually does what she's comfortable doing or offers to do it, if I'm happy I return. I am rarely disappointed because I don't have a preconceived notion of how it will be. Every girl is unique and a "checklist" won't help much in your search for what you seek. ime anyhow 
Others obviously handle it differently.
Your approach to this "hobby" seems like the best, well the best for you, I shall not get spanked for "speaking for all mongers". If I were a hooker, I would very much appreciate this approach.
From many posts on the GD board, I have gleaned that some ladies are not a fan of the check list approach.
face to face. I will sometimes request "can we try" or "let's try" during the session. Bless them, the gals always seem to attempt my request though sometimes it doesn't work out. If there was a special request, like Greek for which prep is likely, I'd ask at one session if could try it next time & how do I let her know when I book?
