If you think having a summer intern is a way to get some cheap labor, then think again. For an internship to truly work, both sides must come out ahead. That means you as prospective (intern) employer must do the due diligence by reviewing applicant resumes, interview candidates and check out references.
It also means you must be willing to make available enough time to provide your intern the tools to accomplish worthwhile goals. (Stuffing envelops doesn't count!)
While all this work may seem daunting, there still are many benefits to your organization. Internships are a great way to screen potential full time hires, especially if the intern is nearing the end of their formal studies. It can also be a great way to train current managers and leaders in the skills of mentoring--in essence, interns have a vast unlocked potential that needs some guidance.