Ports and packages
There are three different approaches for installing KDE Software Compilation, depending on your current setup. Whatever the case may be, you probably want to install ports-mgmt/portmaster to make the process easier.
If you decide to compile from the ports collection, make sure that you have an up to date ports tree (see the Handbook section about using ports). There are frequent upgrades, improvements and bug fixes made to the ports tree, and having the most recent ports tree will help eliminate many already known and fixed problems.
This is the recommended way, since you can always get the latest version in the tree. It will also let you configure several aspects of many ports (with interactive dialogs), but requires quite some time due to compilation. Just run:
# portmaster x11/kde4
You can speed up things a bit using packages for build dependencies:
# portmaster --packages-build x11/kde4
Packages are available on the FreeBSD FTP server. They'll let you skip the long build time, but you won't always get the latest available version. You can install them by running:
# portmaster -PP x11/kde4
This is a good compromise, as portmaster will install packages if they are up to date, otherwise it will build from ports. Run:
# portmaster -P x11/kde4