I was living in Canada at the time, in the district lost by Kim Campbell.
Giles’s short answer is right, but it’s a pretty complicated story.
The “Liberal” part of the Liberal-National coalition is a predominantly urban and suburban party that tends to support a somewhat laissez-faire attitude (in modern-day terms, at least) to economics and social policy. That is, it tends to be push for lower taxes, reduced public services, smaller government, and other economic policies that are sometimes associated with the Republican Party in the United States but, like the right-wing many other western democracies, its policies are considerably to the left of the Republican Party of most economic issues.
Liberals from the cities and suburbs also tend, for the most part, not to be too invested in the culture wars. There’s not the same level of antipathy to homosexuality or abortion that you find here in the US among large swaths of the right. There has always been an element of social conservatism in the Liberal Party, and it seems to me that it escalated when John Howard was Prime Minister in the 1990s and then extended into the 2000s, but it’s not as pronounced as the social conservatism of the United States, and the Liberal Party was, in its earlier days, responsible for many policies that would be considered socially liberal today.
The Nationals are, in many ways, a more complicated bunch.
The party used to be called the Country Party, and the name change resulted, at least partly, out of a concern that the old name hurt the party with urban and suburban voters who, in a highly urbanized country like Australia, make up the large majority of the population.
As the old name suggests, the National (nee Country) Party has been the party most concerned with representing rural interests in Australia. Some of the peculiarities of Australian history and geography make this, at times, a rather difficult thing to do with any consistency.
In many cases, the National Party shares with the Liberal Party a sort of economic conservatism that pushes for smaller government and lower taxation. The problem is that, in a very large country with a small population, there are some services that would never make it to rural areas at all if things were left to the free market, so the National Party and its supporters have often found themselves in the position of defending government programs that help rural and regional Australia. Things like phone service, and local radio and television, would never have been extended to remote areas during much of the twentieth century without government intervention, and so rural voters who often make general criticisms of government spending are also, for example, often strong supporters of the publicly-funded Australian Broadcasting Corporation, because some of the best rural radio and TV programming comes from the ABC.
While the Liberal-National Party is a coalition of the two parties, and unites against the center-left Labor Party, the Liberals and Nationals have often not seen eye-to-eye on economic issues that affect (or are thought to affect) rural dwellers differently. Some of their biggest disputes involved the privatization or semi-privatization of public utilities like Australian Telecom (now Telstra).
The National Party and its supporters also tend to be considerably more socially conservative than their Liberal Party coalition partners.
I’m not sure, however, that all of this was very important in the Queensland election that the OP is talking about. Admittedly, i now live thousands of miles away and don’t follow Aussie politics as closely as i used to, but it seems to me that actual policies were less important in this election than the perception (quite justified, in many cases) that the Labor government that had ruled Queensland for the last two decades was corrupt and out of touch with its electorate. Federal controversies, from leadership squabbles in the Austrlaian Labor Party to debates over a carbon tax, also contributed.