I need to import LAS files to Qgis. I´ve never worked with Qgis till now. Could anybody explain me this problem to the details? I´ve installed Quantum GIS v. 1.8.0.
Not directly, AFAIK. There was a discussion on the gdal-dev mailist a year ago about this question.
You probably want to have a look at the las2ogr tool to get your point cloud into a format usable by QGIS.
Also, be sure to check out how GRASS handles LAS point clouds.