First, let me say that the terms liberal and democrat do not mean the same thing, and neither do republican and conservative.
Let me start with conservative, since I consider myself to be a conservative with a libertarian bent. I guess I should eventually define libertarian too.
The Wikipedia definition of conservative is "Holding to traditional attitudes and values and cautious about change or innovation, typically in relation to politics or religion."
According to the link below, "A conservative adheres to principles of personal responsibility, moral values, and limited government, agreeing with George Washington's Farewell Address that "religion and morality are indispensable supports" to political prosperity.
Former President Ronald Reagan said, "The basis of conservatism is a desire for less government interference or less centralized authority or more individual freedom.""http://www.conservapedia.com/Conservative
However, the conservative viewpoint is often based on radical beliefs and actions, so it doesn't strictly conform to the idea of always being cautious about change and innovation. After all, the conservative often holds to the Christian faith which turned the world upside down. He also supports our founding fathers who definitely fought against maintaining the status quo. Also, it is the pro-life conservative who will take a stand at abortion clinics even though abortion is legal in America.
Jonah Godberg addresses this in his post about conservatism. According to him, it is not easy to define:
I would say that in America, a conservative believes in liberty rather than equality. As relates to money, most conservatives would want lower taxes with the right of the person who earned the money to decide how to use it. This would result in some people who cannot or do not earn money being poorer than the person who works to earn his money.
This is only scratching the surface of the subject of conservatism, but it is a start.