Earlier I was striving to merge and split my PDF documents, as I have a bunch of PDF documents bunch. The moment I found this Handy tool Gios PDF Splitter and Merger, I felt very easy because, it can reduce my most of the troubles.
The tool merges and splits the entire PDF document with ease. The version 2.0 is also able to merge JPEG to PDF, which means you can compose your PDF using scanned documents. Moreover, it is an open source PDF Split And Merge utility for Windows. If you are going to use this tool, you need to install Microsoft .NET Framework version 2.0

Some Important Features :
•    The tool can Split and Merge multiple PDF files at once.
•    It supports to create project that can be used regularly.
•    The tool has no limitations
•    It is possible to control how many pages in a file we need to merge or split
•    It supports page range for user convenience.
•    You can preview the output
•    Create PDF file from scanned document.
•    You can create a file from a scanned document
•    You can have a command line version of this handy tool

From