Install KDE 4.8 packagesInstall KDE 4 Debian packages in your hard disk

There are meta-packages to get you a different subset of preselected KDE packages:

kde-standard Default applications covering most user's needs
kde-full All KDE applications (huge)
plasma-desktop Basic desktop for desktops/laptops
plasma-netbook Basic desktop optimized for netbooks

For those who want a more individual installation, here is a list of important packages:
kdm KDE's display manager (most users will want this)
kde-l10n-XX Translations packages, where XX is your language code
kde-runtime Essential runtime components
kde-workspace Desktop environment
kde-baseapps Core applications
kdeplasma-addons Additional Plasma applets
kdegraphics Graphics applications, including Okular, the famous document viewer
kdegames Assortment of fun games
kdemultimedia Multimedia players and utilities
kdenetwork networking-related applications, such as the Kopete IM client
kdepim Personal Information Management apps, such as kmail,akregator or korganizer
kdeutils General-purpose utilities like ark (kde's archive utility), kgpg or kate (advanced editor)
kdeedu Educational applications
kdeadmin System administration tools
kdeartwork Additional artwork, like wallpapers and emoticons
kdetoys Desktop amusements
kdesdk Software development tools