That's great that you are going to try one of the best ways to help prevent cancer. A monthly breast exam is done just after your period. For those of you on continuous birth control pills, do it on the 3rd week of the pill pack. There are several different ways to do it, in the shower or in front of a mirror is best. What you are mainly looking for is getting used to what the breast feels and looks like (so you can detect changes), and discharges. The Virtual Hospital has a guide with pictures if you need something to look at, as does McGill University.
A description would be more like: while getting a shower or standing in front of a mirror, place your one arm behind your head, and use your other arm to examine the opposite breast. You want to look for changes in size, contour or bulges. Then in circles, press the breast and see if you feel any changes. Squeeze the nipple to check for discharges. That's it! Talking about mammograms:
Its not the most comfortable thing in the world, but is do-able. This exam can make breast cancer deaths plummet. McGill University's article on mammography and biopsy will help you understand what goes on at this time. Mammograms are easier to read thanks to new advances in medicine. There is a blood test for breast cancer, but I don't know much more about it. Mammogram from ThriveOnline appears to be a good resource also.
Bra measurements (anonymous donor who used to work for Victoria's Secret)
Get a measuring tape and measure your back size right under your breast. Don't do it too tightly, just tight enough so it feels comfortable. Then you add 5 inches to the back size.....for example, I measure 31 inches. I add 5 inches to that and it gives me 36. Then you measure around the widest part of your breast. You then subtract your back size from your breast size. If the difference is 1 inch, your cup size is an A; 2 inches is a B cup; 3 inches is a C cup, 4 inches a D, and so on. My breast measurement is a 39....3 inches difference so that makes me a 36 C cup (the most common bra size). Breast information sites:
FMF - Breast Cancer Home Page
Patho.org - Breast Web
Imaginis.com: The Breast Health Specialists (SM)
EduCare: Breast Cancer