first of all, you'll have to unpack the tarball, try tar xvfz <blabla.tar.gz> for gz files or tar xvfj for .bz2 files
this will extract the tarball, you should now have a dir with the source code. with almost every source, there's a README file and a INSTALL file. read both with less README and less INSTALL. most of the times, there's a lot info in those files
most sources are compiled with these commands:
./configure
make
and as root: make install
succes,
-= iluvatar =-