This is a little long, but you wanted to know what the process was like so I'll include it all.
I've been going to Planned Parenthood for hormones and from my understanding they generally work on informed consent.
The doctor at the one that I go to wanted blood work results before writing any prescriptions and said that would usually be the first visit with her; I, however, live about an hour away from that branch (there were none closer that could provide transgender services), so I was informed of the tests she required and had them done through my GP and faxed to her. Once I had the results I called to schedule my first appointment with them. The paperwork they give you at the start is, if I remember correctly, basically medical history stuff (they also gave me a bunch of pamphlets).
During the appointment itself the nurse took another quick blood sample (from a finger prick) and entered info into their system and went over the side-effects of testosterone. The doctor herself went over my blood results and was actually stricter on a few things than my GP (cholesterol, specifically good cholesterol in my case, and blood sugar) and we spoke more specifically about what I was there for. It may be recommended that you seek some sort of therapy, I know my doctor said she typically recommends it even if only to help to deal and cope with the changes and the process of transitioning in general. After all of that she wrote a script for the testosterone itself and we discussed my first dosage.
NOTE: If you want your first dose same day it may be a good idea to mention that when you schedule your appointment. I guess it had not been clear that was my intention/hope and she had to be sure a nurse would be available to do the injection before I went to the pharmacy. I was able to get my first injection that day though.
The next week I went back to learn to self-inject, at which point I was given a script for the sharps (and a bunch more papers specifically on self-injecting). I had a four week appointment to see how things were going, and this coming week I'll be going back for some blood work again. I've been on a half-dose thus far and I imagine my dose will be raised a bit this coming appointment. I've been involved in the process the whole way, discussing it and everything, so it's not as though my still being on a half-dose is the result of a controlling doctor or anything -- I've been nothing but pleased with the staff as a whole there.
All of this said, it seems one's experience with PP varies depending on which branch/doctor you go to: they're all a little different. I've been pretty satisfied though, especially as they have me in their system under my preferred name and refer to me as such and with proper pronouns (and are apologetic when they can't use my preferred name, such as on more official paperwork and in the case of insurance).