Conservatism as a political doctrine
While the word Conservatism is often used to describe merely an attitude of supporting how things currently are, it can also refer to a political doctrine that originates in Edmund Burke. Conservatives are not opposed to progress per se, although they are often more doubtful about it than followers of many other ideologies. Conservatives do not reject reason completely, but they place much more emphasis tradition or faith than is common in politics today. According to the author of the Conservatism FAQ, the essence of conservatism is "its emphasis on tradition as a source of wisdom that goes beyond what can be demonstrated or even explicitly stated."
Conservatives emphasise traditional instiutions such as the family or the church, which they see as more personal than either the modern state or corporations.
Within the United States, there are several distinct elements in the conservative movement. Neoconservatives originate in American liberals, primarily from the Northeast or the West Coast, who during the 1960s began to move starkly to the right. Palaeoconseratives, by contrast, originated in other parts of the United States; they lack the background of having formerly been proponents of liberalism.
Conservative views on the economy often overlap with those of libertarians, but they disagree with the libertarian position on social issues. However, there are some libertarians whose views on social or cultural issues are closer to conservatism than most libertarians are, such as Llewellyn Rockwell or Murray Rothbard; these are sometimes called palaeolibertarians.
Other sources of the thought of some conservatives include the distributism of G. K. Chesterton and the French traditionalists (e.g. Henri Corbin). Some conservatives have also originated from the Frankfurt School, after taking (like the neoconservatives) a turn to the right; such are the editors of Telos.
Palaeoconservative publications: Modern Age, Chronicles
Neoconservative publications: Commentary, The Public Interest, First Things (has expressed controversial attitudes towards religion and against separation of church and state that many other neoconservatives reject).
Conservatism as an attitude
Conservatism is the attitude or lack thereof that justifies whatever state of things currently are.
In a communist country, conservatives are communists. In a mercantilist country, conservatives are mercantilists. In a social-democrat country, conservatives are social-democrats. In a feudal country, conservatives are for feudality. In a libertarian country, conservatives are libertarians. etc.
In this sense conservatism is not a consistent ideology per se, and does not refer to any particular idea, unless a reference is given as to the country and times considered.