I was a first time mom and did have a wonderful doula. Don't know how much was different than any other first timer. Although I did have a homebirth.
My doula was wonderful. She brought the best cookies and just hung out with me through the whole process, very patiently. I probably called too early, but she went with it. She walked with me, and talked me through things. Just awesome moral support from someone who had BTDT fairly recently, and in a way that freed my mom and DH up to attend to other things - like food for the midwife and her assistants, checking on the birthing pool.
So sorry, no good twin-specific suggestions, but best wishes! My doula was one of the best parts of my twin birth!