Depends on which iBook model. Also I recommend against buying no-name memory for use in Macs, as Macs tend to be rather picky about their RAM. Buy some from Kingston or Crucial.
No. This is desktop RAM (if the link is correct, it says "Patriot Signature Series 184-Pin 256MB PC-3200, Model PSD256400 - Retail") and for your iBook, you'll need 200-pin DDR SO-DIMMs. It's also best to buy PC2100 or 2700, depending on which type your iBook uses, because notebook memory doesn't always slow below its rated speed gracefully. By that, I mean that PC3200 notebook RAM might not work in a system designed for PC2700, for example.