Paste them in?
I'm sure there are better solutions, though. iPhoto comes to mind, as do several online photo storage sites.
What is missing from your question that might affect the answer?
Thanks, but I'm totally new to Pages and don't know the first thing about pasting things in. Where would I paste things? How does it compare to Microsoft Word, where I could just open a document and cut & paste? What I'd like is one handy place on Pages to access photos I've collected for a book I'm putting together.
I've had less difficulty cutting and pasting images into Pages than has been my experience with Word. I do find that doing so creates rather large documents, though, and they tend to slow down a bit as they grow larger.
Pages accepts images as either floating or inline objects, and the differences between them and their behaviour may give you some difficulty until you get a feel for those differences.
What you're asking seems doable, but there are probably better applications for managing an image library.
You might want to read Chapter 7 Working with Images, Shapes, and Other Objects, in the Pages '09 User Guide before proceeding too far. The guide is available fro download via the Help menu in Pages '09.