My employer has a blog series that covers many of these issues with skeptical Christians as the intended audience: http://biologos.org/blog/series/evolution-basics
In fact, in an ideal world, evolution wouldn't be an important thing for most people to understand. It is disproportionately important because it is the point of attack of fundamentalists against scientific modernity, and a naive view of evolution can leave people susceptible to their propaganda, and therefore more likely to politically oppose science.
If the standard for accepting a theory is absolute understanding, then the human race won't get very far. I subscribe to various theories about physics (ie gravity). I don't claim to understand them. But I do not dismiss them simply because I lack a complete understanding. I trust those scientists who do.