I'll post what I did in another thread, since I just did it.
Libertarians are fiscally conservative. They want lower taxes, laissez faire economy, etc. They're also socially liberal. They will allow people to do anything, as long as it doesn't hurt anybody else. So, a Libertarian would say people could do hard drugs and marry their brother, but if they get aides or have a retarded child from inbreeding, don't expect to get any government grants to help you out.
Contrast with a liberal. They would say that you could do these things, and whatever bad came from it, the government would be there to keep you on your feet.
Contrast with a conservative. They would say you shouldn't have been doing those things anyway, so your not going to get any help.
There is a saying: Conservatives want the government to be your daddy. Liberals want the government to be your mommy. Libertarians want the government to treat you like an adult.
/stereotyping.