If your appointment is anything like mine (from Solihull) you're essentially asked for certain documents and you hand them to the person. The longest part of the process was waiting for the vignette to be printed.
Also, Solihull isn't doing Biometrics yet, but here is exactly what they asked us for across the counter...
* Application (form FLR(M))
* Passport-sized photos (2 of me, 1 of DH)
* Passports
* Husband's bank statements and payslips (he had 2 payslips and a stamped printout from The Halifax)
* Marriage Certificate
I also had prepared a budget listing my potential wages once I am able to work & an employment offer letter, along with an envelope holding onto all of our previous documents from the fiance visa...but she said it wasn't necessary to see it. So, not a bad idea to perhaps bring more than you need, but if they ask you to hand them certain documents, don't be surprised if they don't ask for everything you thought you might need.
Good luck...and let us know how it goes! xx
**EDIT: Remember to still use your maiden name if that is the name your passport is still in. I almost filled out my married name on my form when my passport has my maiden, hehe. Just call me an eager beaver.