If you want an easy way to install packages from source, without going into command line, see this topic. Try to get hold of the mentioned software using Synaptic or any other package manager.
If you want to compile the software from within the command line, check the numerous guides available -
*www.tuxfiles.org/linuxhelp/softinstall.html
*www.linuxgazette.com/issue74/okopnik.html