What are my chances of understanding radiation and risk?
Pretty good, I'd say. That's DMW's job (except that he's retired).
Many people are not used to dealing with “orders of magnitude”--the powers of 10 that separate a large risk (of getting a cold during your lifetime, for example) from a small risk (say, being hit by lightning). Because every aspect of radiation—how it is measured, its effects even on a cell (not to mention a human population)—is statistical, understanding why it is safe to live around (or visit) the Rocky Flats National Wildlife Refuge may not be easy, depending on your background.
The chance that you'll be living on or visiting radiation-contaminated ground here is 100%; the same could be said of the entire Earth, since there is natural radioactivity everywhere and yet more after the nuclear weapons testing of the 1950s-1970s. The chance that you will receive a dose of “ionizing radiation” when you get an X ray (but not an MRI!), a CT scan, a mammogram, or even when you get a suntan? Also 100%. Thus understanding the health effects of nuclear radiation is entirely about becoming less uncomfortable with orders of magnitude and the statistical description of health outcomes for large numbers of people.
Almost all of the technical documents in the Knowledge base part of this web site are devoted to getting readers comfortable: with radiation and its effects on living organisms, with the study of disease rates among large numbers of people (epidemiology), with the fact that there are large and small radiation doses (and what this even means), and with how such exposures translate into a lifetime risk (probability) of cancer, the main health impact of (largish) doses of radiation.
We urge you to begin by reading the document How people think about radiation, then Cancer epidemiology, then From radiation dose to cancer risk , and finally Rocky Flats, radiation, and risk , the single most important document on the web site.