Probably not the right way to do this, but works for me....
I'm a new Pbook owner, and I just connect the two laptops with an ethernet cable (directly, bypassing the router).
Find the IP address associated with your ethernet (click the apple in the far-upper-left corner of your screen-->"About This Mac"-->"More Info..."-->Click on the "Network" tab and find the address next to Ethernet).
On your windows laptop, just go into Windows Explorer and type in "//192.168.0.1", using your Ibook's IP address behind the double back-slash.
It may take a moment, but your windows laptop should connect/find the Ibook, then ask you for your Ibook's username/password. Then you should be set to go. Hopes this helps.