Career Development at Stanford Career Development Center - Stanford's job placement site. Provides help in building your resume and provides potential employer contact information (albeit, non-industry-specific) as well as information about university wide job fairs and recruiter visits. Well worth a visit to their offices. Financial Industry Related Courses - Read about the relation of various courses offered in the program to the different types of jobs in the financial industry. Use this as a guideline for customizing your study list to best fit your post graduation goals, and in directing your job search to the positions for which you have a relative advantage.
Stanford Alumni Association - Keep in touch! Once you graduate, post your profile under "Financial Mathematics". Plus, search the Stanford Career Network for alumni who will provide resume critiques, informational interviews, and whose companies may offer internships. This is a terrific way to network with alumni in the field (from Financial Math and other programs).