Pathways to Science is an excellent resource for finding programs and other funding opportunities. Pathways to Science is a project of the Institute for Broadening Participation (IBP). Pathways to Science supports pathways to the STEM fields: science, technology, engineering, and mathematics. We place particular emphasis on connecting underrepresented groups with STEM programs, funding, mentoring and resources.
Biomedical Science Careers Program
New England Resource Directory
Tufts University Health Professions Advising (see tabs on the left side for access to list of summer internships)
The Schmidt Lab at the University of Georgia put together a great list of agencies to peruse!