You can get the most recent version of Scribus from:
There is also thanks to Anduin.net, anonymous SVN access is updated daily. Only recommended for those who want to stay on the bleeding edge. Scribus 1.2.x is now deprecated. Instructions for getting the latest source via cvs:
Scribus 1.3.3.x - Stable
svn co svn://scribus.info/Scribus/branches/Version133x/Scribus
Scribus 1.3.5svn - Development - Qt4 Port
svn co svn://scribus.info/Scribus/trunk/Scribus
Either choice will then download the sources to you into your current working directory. Then:
cd Scribus make -f Makefile.svnor optionally use cmake. Cmake is required for 1.3.5svn, as autotools support has been removed.
From here, continue with the Compiling and Installing instructions.