Graduate School
In addition to doing well in your classes, it is also critical that you gain research experience. Talk to one of the Upstate Biology or Chemistry faculty members about getting involved in research.
Also consider applying for a National Science Foundation Research Experience for Undergraduates (REU) Fellowship. There are a lot of REU programs in Biology and Chemistry. For an REU, you will conduct research in a cohort of undergraduates from around the country at a large, research-intensive university. You typically get a nice research stipend and free room and board with an REU. They are competitive (often take ~12 applicants from a pool of 250+) so apply to several programs.
Medical School
In terms of what helps you get a medical school interview and then (hopefully) an acceptance letter, check out the data below from the Association of American Medical Colleges Analysis in Brief Reports (Volume 11, Number 6, Sept. 2011). You can find more of these reports on medical school admission at the AAMC website.
Students generally take the Medical College Admission Test (MCAT) the summer after their Junior year. You will also want to start working on your AAMCAS application during the summer after your Junior year. It is very important that you DO NOT wait until the deadline to submit your AAMCAS application as many schools have early admission and the spots may fill quickly.
In regards to studying for the MCAT, you should start preparing several months in advance. Websites such as the MCAT Question of the Day are a useful study tool. In terms of test preparation books, I have had a several students recommend the Exam Crackers study books. I recommend taking full-length practice tests as the MCAT test day nears. This will help you build “intellectual endurance” to withstand the length of the MCAT on test day. Past students have told me that their performance on a full-length MCAT was a good predictor of their eventual MCAT score.
You will also need to spend time volunteering or interning with a doctor. If you wish to work with a DO (osteopathic physician), you can find local doctors by searching the American Osteopathic Association website.
Getting Health Professional Volunteer Hours
Consider volunteering for the free dental, optometry, or medical check-up clinics at Miracle Hill or the St. Lukes Free Medical Clinic in Spartanburg. Not only will this help you gain volunteer hours, but you will also be serving the Spartanburg community. I strongly recommend keeping a diary of 1) hours worked and 2) a listing of what tools/techniques you helped with for any volunteer or internship time.
Reviewing for other Graduate and Professional Exams