Both CIA and NSA have a student internship programs, which come in to play for college students. These are extremely competitive, and the earlier you apply the better, even before you get to college. Interns get paid and usually go on to career positions. DIA's Summer Intern Program provides promising undergraduates and graduate students the gain valuable work experience during temporary employment with the Defense Intelligence Agency. The position available are Intelligence Officer, Computer Specialist, Engineer, General Physical Scientist, Human Resources Manager, and other Support Officer Occupations.
Intelligence is one of hundreds of career fields in the uniformed military.
Keep in mind that one aspect of military service is that you must go where they send you. Every three or four years. So you may end up fixing helicopters, driving a truck, or whatever. It is also the best way to apply for jobs or to contact the agencies. These include the Commerce, Energy, Treasury and State Departments.