If you're just doing something really easy like clipping pages out or reordering pages, pdftk is great. It's a command line tool.
For example, to remove page 4 of an 8 page pdf (example.pdf), use the following:
To combine pdf's first_file.pdf and second_file.pdf into first_and_second_file.pdf, so the following:Code:pdftk example.pdf cat 1-3 5-end output new_pdf_file.pdf
Easy as pie, and I find it really useful.Code:pdftk first.pdf second.pdf cat output first_and_second.pdf