Second Year of Undergraduate Program
So, you made it through first year, now what? I feel that second year is an important time to actually start doing things for the purpose of getting into medicine.
Academics
The focus during year two should be working toward your prerequisites, and courses that prepare you for the MCAT. Also, many schools will require you to choose a major at the end of this year, so put some thought into that (see the discussion about choosing a major on the first year page.
Volunteering
If you are not, you should be! Click here for some tips.
By the time the upcoming summer rolls around, you will have enough science behind you to start applying for research work. The professors that supervise you make for great reference letters, and you may even end up publishing. The pay generally is not very good, but the experience makes up for it. Anyhow you need to be setting this stuff up around December, so start making some contacts. Go here to learn a little about my research experience.
MCAT
In my opinion, the summer between second and third year is the best time to write this exam. Click here for more information.
Applying to the Schools
At many schools, you are eligible to apply after completing two undergraduate years. It is important to note that very seldom does anyone get in at this point (you hear of it every now and then). Anyhow if you wish to apply, you should have written the MCAT last summer. Your application will be due in October - December of this year.