-4 years undergraduate
-4 years medical school
-USMLE step 1
-3-7 years residency (specialty dependent: pediatrics 3, surgery 7, others in between)
-USMLE step 2, 3
-1-4 years fellowship (definitely optional)
It's a long road with lots of hurdles! I'll be 30 by the time I'm board certified! (but I did take two years off between undergrad and medical school for the Peace Corps)
This isn't quite accurate.
4 years of undergrad, possible less or more depending upon how you structure your courses and how much you can handle. More likely, how many times you do or do not change majors. MCAT usually in your junior year, applications in senior year.
4 years of medical school
USMLE/COMLEX part I at the end of your second year of medical school. USMLE/COMLEX part II and part II CS/PE in late third year or early fourth year. During fourth year are your "audition" rotations/elective, applying for residency, going to interviews, etc. It's basically like applying to medical school all over again.
Internship
Similar to fourth year but a lot more responsibility and autonomy. USMLE/COMLEX part III at some point during this time.
Residency (2-6 years depending upon what you do)
Yearly in-service exams. Get your unrestricted license starting PGY2 (if you have passed part III and intern year) and are able to moonlight if the program allows. Family Medicine residents were making about $65-$70 an hour moonlighting in the ER their second and third years.
Fellowship (1-3 years depending upon your field)
Further subspecialization training (such as Forensic Psychiatry, Addiction Psychiatry, Gastroenterology, Infectious Disease, etc). Usually adds a nice bump to your yearly income and gives you a "niche" to practice in. Sometimes, it doesn't add anything but knowledge.
Attending
I left this category broad because you can do pretty much whatever you want at this point. Private practice, hospitalist work, faculty at a medical school, etc.
From college to attending is at minimum 11 years if everything goes perfectly. It usually doesn't.