Our daughter turned 2 exactly one week before I had our second child - a boy (we didn't know the sex). we didn't do too much extensively before the baby was born to prepare her except involve her as much as we could (she talked to the baby, kissed my belly, we talked about how she could be a big helper and how exciting it was going to be to be a big sister) I also bought a book called "I'm A Big Sister" by Joanna Cole (they also have "I'm A Big Brother". We read it daily and I know hear her saying things from the book to her little brother. We also bought her a "Best Big Sister" shirt so she had a special outfit to wear to the hospital and that got her some extra attention from the nursing staff which made her proud.
Another thing that worked well for us was when our daughter came to the hospital for the first time, my husband went downstairs to get her from my dad and when she came into the room, the baby was in the bassinet so she couuld run over and jump in the bed to see me and spend a few minutes with me and then we introduced her to the baby. She didn't want much to do with him at first (just looked at him) but we didn't force her to hold him or kiss him, etc and she decided when she was ready. She LOVES her brother!
Good luck!