Part and parcel of the procedure is that a proposal needs to be written and approved by the supervisor or coordinator. The proposal should explain what kind of work will be done, the name and contact details of the organization, how local supervision is arranged and how contact with the chair group's supervisor is established. This information will be part of the internship contract that will be signed by the student, the local supervisor and the chair group's supervisor.
In certain circumstances, it may be advisable to link internship with the (major or minor) thesis. Contact your study advisor and the chair group internship and thesis coordinator.