C.G.
A birthing class can be helpful- particularly one that covers what to expect in a c-section which can be scary if you don't know what's going on.
I know you didn't ask this so I hope you don't mind me putting my .02 in, but I would recommend you do some research on twin deliveries and see if you would like a second opinion on your delivery choice. It looks like you are a few months along. Remember that a c-section should be a last resort. For well-positioned twins (which you wouldn't know until the end of your pregnancy) a vaginal deilvery is a safe choice. I work as an RN and student midwife in a major academic medical center and twins are born vaginally frequently as the doctors there try to avoid unnecessary c-sections.
In the absence of complications a vaginal deliveries are best for mom and baby and don't carry with them the risks to future pregnancies that c-sections do. Above all congrats on your little blessings and best wishes!