A nice brief interview in the National Review which helps lay out one man's understanding of the difference between liberalism and conservatism:
. . . what separates us at the most fundamental level may be our different conceptions of liberty. Conservatives value above all else what Berlin called the negative vision of liberty, namely, freedom from coercion. Liberals are more willing to balance that against the positive vision of liberty — that is, having a reasonable opportunity to realize one’s potential. The negative vision focuses conservatives on restricting the government’s ability to interfere in people’s lives. The positive vision leads liberals to believe that government has a role in guaranteeing baseline minimums in education, medical care, and healthy communities. Most of us probably accept both visions to some extent, but how we balance the two may be built into our DNA. It is not to be expected, therefore, that a liberal will be converted by reading the great works of conservatism, or vice versa. But there are rewards to be gained from doing so nonetheless. Often, we get a better understanding of what we believe by reading about a philosophy with which we have disagreements than by reading congenial literature. More important, reading its great works helps us better understand — and respect — the other side. That, at least, has been my experience.