DS 2019 Form J1 Visa
To apply for your J1 Visa you will need to obtain the DS 2019 form. This document can only be issued by Sponsor Organizations in the US. These Sponsor Organizations are designated by the U.S. Department of State to verify if the student, the internship and the internship company meet the J1 Visa requirements. In return the Sponsor Organization charges a fee for this service. De fees differ per internship duration, intership company and Sponsor Organinization.
Always make sure you pay the above fees directly to the Sponsor Organization in the United States and not the internship agency's in Europe. If you do pay to European Agency's, you often pay a high commission of hundreds of Euro's extra for the DS 2019 form/
Here you can find an example DS-2019 - Training Plan.