At this point, you should really be keeping an updated CV instead of a resume. There are some differences and your school will hopefully offer some guidance or have some support to help you get yours nice and polished. Update it every 3-6 months so you don't forget things you did. As to your question: shadowing no, but everything else yes.
Very basically, your CV should include:
Name and CURRENT contact information
Education (after high school), including your MD (just put the year you'll get it, don't say "expected;" people know what year it currently is). Include any greek honors (cum laude, etc).
Honors and Awards - major scholarships, awards, eagle scout, etc. -- any kind of recognition that you can slap a name on, put it there
Professional/work experience -- every job you've had unless it was shady and weird; you may use "professional exp." and "other work exp" as two separate sections if you want to keep your medical-related stuff separate from your fast food job in high school
Teaching experience - you can list this under work but I break it out as a separate section
Research experience - I list my NIH grants and other funding, ongoing projects, editorial board positions, etc.
Publications - self explanatory
Presentations - self explanatory
Leadership - board of director positions, officers in clubs, groups you've founded, etc.
Community service - volunteering, free clinics, soup kitchens -- whatever you do to give back
Professional organizations you're a member of
Languages you speak (if more than 1)
Hobbies and interests