g4 titanium powerbook install questions

[jason kahn <kahn@attglobal.net>]

hello list
i recently installed debian 3.1 on my g4 titanium powerbook (1 ghz 
processor). the install went basically ok, except for the following 
problems. i am new to linux and an am not sure how to correct the following:
screen resolution: i would like to have 1280x854; i can only now choose 
between 800x600 or 648x480
sound: does not work.
external devices: when i plug in an external hard drive it doesn't 
appear anywhere.
any help is greatly appreciated.
best regards
jason kahn