You see a Psychologist, Dietician, Specialist Nurse, Anethetist, and a medical doctor (the one I saw was an endocrinologist) in the morning. Just be open and honest with them, you go through all the reasons for having the surgery and all the potential pit falls. They will ask you which surgery you want, and they will discuss with you if this is your best option.
Then after lunch you will be called with others or on your own to see a member of the team who will tell you the decision. After that you will see the surgeon who will address any further concerns with you.
No problem about family or friends. I went on my own, as I felt I would be better just worrying about myself. Its a very long day, I did't leave until 4pm.
Also don't worry too much about not being accepted ( because I did loads), those that were not put through, it was because they had not researched fully, or were unsure.
They say bring a book, but I was so busy I didn't have time to read it!
Mine was 19th October.