Hi kakapo!
Sorry for my (probably bad) english, I'm Spanish.
If you use RedHat, Mandrake or SuSe, you've to download the aMule RPM file, and, from the console, enter:
rpm -ivh file.rpm
(where file.rpm is the aMule rpm file -remember insert the caps correctly-).
Else, you've to compile the source. Extract the source code to a folder and, in the console, write ./configure. If you don't got any error, try doing a "make" and "make install" later.
For start aMule, run "amule", from the console or from a icon in your desktop (if you use a desktop like KDE or Gnome). If you cannot share your files, run aMule writing it in the console:
export LANG=C && export LC_ALL=en_EN && export LANG=en_EN && export LC_MESSAGES=C && amule
If you don't want to write it when you want to run aMule, you can write it in a file and save it in /usr/bin/ (or /bin/) with a name like "amule2". For run it, only write "amule2" in console or from a "run program" menu.