Working with PDF Files
Use the PDF Toolkit to split and merge PDF files.
Rotate Page
This is useful if your scanner outputs PDF files and sometimes the image is on its side:
$ pdftk printer_001107.pdf rotate 1right output snowman.pdf
Extract Pages
$ pdftk document.pdf cat 5-7 12-15 output extract.pdf
Concatenate PDF Files
$ pdftk file1.pdf file1.pdf cat output combined.pdf