Except for this: Most kids get summer jobs—"internships" if they're of college age—with no idea what they are doing. Still, any job is good for these kids. They learn basic skills, like getting up on time and showing up with brushed teeth. Personally, hard work made me what I am today. I spent summers helping my dad farm and I wanted NO part of it as an adult. The point is, we all learn from these first jobs.
Your last job as a parent is get them ready for the real world, the world of work. You know two things they don't: Their weaknesses and what kind of job would be "good for them."
My son was in business school and his official internships were on the trading floors of investment banks. But his best summer job was when he was a short-order cook. He needed this dose of reality, humility even. I could have helped him more, but he didn't do badly.
Two guiding principles:
G.L. Hoffman is a serial entrepreneur and venture investor/operator/incubator/mentor. Two of his companies have traveled the entire success path from the garage to IPO. Currently, he is chairman of JobDig and his blog can be found at WhatWouldDadSay.com or at JobDig.com.