Students in class (and office hours) will recall my mentioning inexpensive online classes to supplement college/university classes and as a useful way to build skills before transfer, grad school, or med school. These Massive Open Online Courses (MOOCs) feature leading international universities with two of the largest course sources being Coursera (coursera.org) and EdX (edx.org).  Whether you want to brush up on biostatistics, take a programming course, or learn about infectious disease, you will find it on either of these sites.  Edukatico.org and class-central.com are 2 websites that gather listings of online courses as well as student reviews.