package qgis is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source. E: Package qgi has no installation cadidate.Messing around in google i found the way, how to correctly install qgis on Karmic.
Copied from ubuntugeek.com
First you need to open the terminal and run the following command
sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable/
Update the source list
sudo apt-get update
Install qgis using the following command
sudo apt-get install qgis
Following the perrygeo.net instructions I tried to install other software, like GRASS and its plugins, mapserver-bin, gdal-bin, python-qt4, python-sip4, but I got message in terminal that these packages are already installed (assuming they`re installed together with QGIS).
Of course. perrygeo.net article is written 3 years ago... no more wonderings.
But still i was able to install python-gdal, cgi-mapserver, python-mapscript, gmt (which includes gmt-coastline-data), r-recommended, gpsbabel,
But still (x2), I bet, it is very good place where to start. For true newbies, like me.