@nubechecorre
Don't quote me as I am no expert in these areas (perhaps ktadd can comment) but I think ffmpeg provides divx playback.
Add these to your /etc/apt/sources.list (one or all then apt-get update)
deb
http://www.debian-multimedia.org lenny main
deb
http://www.debian-multimedia.org stable main
deb
ftp://ftp.debian-multimedia.org stable main
Also ensure you install xine-ui and libdvdcss2 (if it is legal in your country).
If you want to try and RIP DVDs then try installing k9copy.
Good to hear printing is fine. I have found printing and scanning (use libsane, xsane or kooka) so simple under Debian (and Ubuntu on my high end PC), much more so than under Windows.
@Cara
Type apt-get install gcc in a terminal and it will install for you so long as you are root, or try sudo apt-get install gcc. Do this in a terminal and it will suggest some other packages to install which may be useful to you, many are doc or help files but some other tools as well.
What package are you after? There is a good chance it will not work on PPC if it does not already exist.
Hope this helps.
ace