This may help, but ICMA has an internships guide that has some good information on creating internships at http://icma.org/internships. I think benefits of a centralized internship program include the following:- Building a network/friendships among the interns themselves- Providing an opportunity to have training/professional development for the interns together (more easily than if they are in separate departments) - Job-sharing, or having many interns work on one larger project, or allowing them to "ramp-up" if a project needs more people for a short time- They can help each other solve problems; there is a large focus on teamwork in grad school, and modeling that at work can take advantage of/reinforce this training and get more minds on a problem. They can also learn from each other.- When new projects or needs come along, you can always go over to the "intern squad" like a skunk-works. "We have this new project...who's in?"- Their teamwork/togetherness will help create bonds and support that will help them when they need to present projects before council, department heads, etc.Those are some thoughts!