HP is usually considered to be good for support for Mac. The HP printer we got last year (psc2100, printer-scanner-copier all in one), and both of the HP printers we had before that (one was bought 1998/99-hpdeskjet810c and the other is from around 1994/95- not sure what model), have instructions (the large poster instructions have mac on one side, and windows on the other) and software to set up the printers for Macintosh computers.
Have you tried just plugging in the printer? Maybe the iBook will be able to recognise and use it without any drivers. And I assume you have checked the printer software/instruction manual to see if it has anything relevant to Mac OS? I have looked at the HP/Compaq site, and can only find Windows 98, ME, NT, XP drivers myself. Sorry I can't be of any more help, and its a pity if Compaq doesnt support Mac, but HP does, especially seeing HP owns Compaq.