How do I cook sausage links in a crock pot.?

I know very little about anything food related. Im a teacher and I am making my kids a breakfast. It will be for about 30 students, so im making about 60 sausage links. I figure the easiest way would be through a crock pot. How can this be done. I thought about cooking them over the oven first and then just placing them in the crock pot to stay warm. Do i need to add water to the crock pot to do this? OR cold i just put them in the crock pot tonight and then they cook over night? If i can do that, do i just cook them in water? ANY TYPE OF HELP WOULD BE MUCH APPRECIATED