Edit and merge PDF files
Two useful PDF softwares, which help to edit and merge PDF files. These come as free downloads, and have helped me edit and merge some of my PDF files with ease.
Edit PDF files with PDFill
Free utility PDFill can create, update and merge existing PDF files for free. PDFill can also split or reorder PDF pages, encrypt/decrypt PDF’s, rotate and crop, add image or text watermarks, and convert images to PDFs and back.
The only drawback is that, it requires Java runtime to work, but it can be easily ignored considering its usefullness. It is a free download, for windows.
Download free: PDFill
PDFMerge combines and splits PDF files

A small application PDFMerge combines and splits PDF files. Specify page ranges from each document you’re merging and manipulate bookmarks, too. Preserve existing document bookmarks in a new bookmark tree or omit them altogether.If you want more try PDFill.
Download PDFMerge free:PDFMerge

That tool is excellent for any black hat SEO, thanks.
[...] does not support extraction of PNG files which are used mostly these days. On my earlier tutorial, How to edit and merge PDF files I have written a guide to edit PDF files. Perhaps you can also save image files using it. Try it [...]
PDF Editr and PDF image extractor are good applications, because it improves the usability of PDF files a lot.