There are ways to catch a new intern up to speed without killing your own productivity. If you don’t want to regret the whole intern experience, it’s important to take some of these steps to save yourself headaches.
Create training materials: Spend some time creating instructions for how to accomplish various tasks interns will have to complete on a regular basis. A shared set of Google Docs (docs.google.com) is probably the easiest way to share these sorts of resources. A set of word documents on a shared computer drive is also very easy to create and manage. Time invested up front creating instructions will pay off many times, especially since interns sometimes need to refer back to instructions multiple times as they get the hang of new tasks. (The alternative is being prepared to explain the same thing over and over again.)
If you have a microphone, it is extremely easy to record and narrate “screencasts” (videos of your computer screen) to show how to do certain things. There are many websites that allow you to create a screencast for free (such as www.screencast-o-matic.com), without requiring you to download software. If you can record these videos without revealing proprietary information, you can upload them to Youtube for easy reference, and link to them from your written instructions.
Rely on the expertise of veteran interns: If you take on more than one intern at a time, veteran interns can be an excellent training resource for greener interns. Interns generally enjoy sharing their expertise and knowledge with trainees, and they learn more through the teaching process than they otherwise would.