Program for creating PDF books

So I want to put together a PDF book / booklet and was wondering if there's a program out there that would make it pretty easy to put together. Almost like a power point creator, where I can drag and drop pictures, select backgrounds and copy and paste text and fool with formatting and everything.

Mac software would be preferred, but PC would work as well. Thanks in advance for any recommendations.

EDIT: Nevermind I didn't realize you could save as PDF in Word... Maybe that'll work. Though I'm not sure about adding backgrounds and such to the pages.

You can use PDF-Viewer for editing and adding booklet

You can save as PDF in PowerPoint too, I think!

Adobe InDesign. Probably some open source clones out there as well.

* found this open source MAC clone http://www.scribus.net/canvas/Scribus