Unless you have Adobe Acrobat, it’s hard to find tools that allow you to play around with PDFs. For viewing i stick to Foxit for now, as it’s the fastest thing around. But when it comes to merging, there sure is a lack of good free tools. I looked at and some other ones, but they were purely crap.
The best tool i found was pdftk, the PDF Toolkit. It’s a simple exe that you copy to your system path and merging files is as easy as
pdftk 1.pdf 2.pdf 3.pdf cat output 123.pdf
It also allows you to merge/split files, update meta data etc. You can check out its page for more details.
