Basically, lots of form filling!
Check with your DH before you go as to whether there's any history of family illnesses you need to be aware of, as you'll be asked about that. There's a lot of questions to answer on everything from previous pregnancies to mental health, drugs and alcohol, health issues, etc etc.
You'll do a urine sample and have bloods and blood pressure taken. We also do a carbon monoxide test in my area, though I understand that's not nationwide.
I wasn't weighed, but the midwife ticked a box saying "healthy BMI" - presumably if it's not obvious your BMI is healthy just from looking at you, then they'll weigh you.
Erm...Think that's about it? I wasn't asked much about birth choices but I suspect that from looking at my notes and seeing what happened with DS1s birth, they'd guess I was just going to go for hospital again rather than a home birth.
They put all my details in the system and I got my dating scan appt a couple of days later.
With my first pregnancy I was also given a bounty pack and a load of leaflets,but I wasn't this time. Oh, and they asked if I was planning on breastfeeding again.
Think that was about it!