Alex is right. If the iBook is running OS X 10.0, that needs to be upgraded, too, to a more modern version of the OS.
By the time you go to the expense of upgrading the hard drive and the OS, you're well on your way to the price of a better iBook.
If you're determined to keep the clamshell iBook going, you may want to try posting in the
iBook (colors) Forum. (You have posted in the iBook G3 (Dual USB) Forum, the forum for the first all-white iBooks).
Users in the iBook (colors) Forum can advise you on the best upgrades for your model.
Good luck.