Most likely you have 64 Megs on the motherboard and 64 megs in the slot. You can replace the slot with 1- 512MB SDRAM SODIMM for iBook G3.

I have my Graphite 466 upgraded as follows

160GB Samsung 7200 rpm hard drive

an extra 512mb of ram

Running OSX 10.4.11 very well.

Stripped the OS down with Monolingual and use TENFOURFOX as web browser.

Makes it a very useful tool ,and quicker than many expect.

If your ibook doent have firwire (my wifes tangerine doesnt) OSX 10.4 can still be loaded by using a great bit of programming called Xpostfacto.

When i first got my clamshell ,it was considered redundant , but they seem to have a core group of bodgers willing to make strides to get them to operate well above their limit.

Good luck.

According to Mactracker, the maximum OS is 10.3.9, you can have a maximum of 128 GB per drive, you can install an airport 802.11b card (if not already installed), and your maximum RAM is 576MB (a 512mb and a 64GB card would be what you need).

To further expand upon Mayer's solution, you won't actually be able to upgrade to 10.4 unless you pull some strings- you'll need to follow the instructions given here.