DIY Book Scanner

for instance, originally the cover is page 1, preface is page 2 in the PDF etc etc,

but for the book itself, its page 1 starts either on the real content or table of contents. i've seen some PDFs mapped their pages to the book order. how do i do that?

You may want to repost this in the software section. Also, what program are you using?

I use Abbyfinereader. If the page numbers were in the pictures as I was scanning, they'll be in the final pdf. As far as changing the pdf's page numbers so it matches the book, I'm not sure you can do that.

If you have Adobe Acrobat, you can change the numbers. Open the Page Thumbnails tab, then select the pages you want to renumber. You can set the start number to use, and Acrobat will automatically fill in the range from there. I've used that to fix up page numbers before - for example, books with roman numeral prefaces before the "proper" page numberings tarts.

http://sourceforge.net/projects/pdfsam/

Opensource and free. Takes a little bit of trial and error to learn, but it's effective. Also able to edit pdf files regardless of which version / format of Adobe Acrobat the original was created in.