Many companies have formal internship programs and regularly advertise for these positions. If however, there is an organization where you’d like to work, but you don’t think that it has an internship program, be proactive about creating your own opportunity.
How can you best do this?
Research the organization thoroughly. Determine in advance why the department should take you on as an intern, and what value you can add to its current work. What specific strengths, previous experience and transferable skills can you offer?
Contact a person working in the area where you would like to be, and offer to work as an intern. If the organization is in the non-profit or public sectors, let him/her know that it is likely you can get supplemental funding from Mount Holyoke College (see Lynk UAF for process and policy). Be clear about why you are approaching this organization (or person) specifically, and what you have to offer. Not sure how to reach out? This Inquiry Letter Guide may help.
Remember, it is in your interest to make the process as easy as possible for the hiring manager. Keep your goals in mind, but be enthusiastic and flexible–especially if he/she has never had an intern before!