Siblings helping with a new baby?

Va
For those who have more then one child already, what are their ages, and how do they help with your youngest child? I have a 5.5yo, and baby #2 due in October. One thing I think will be nice is having another child to help entertain a baby. I don't have expectations of help beyond that, but I am curious to know how your kids help care for each other in your house.