There are many programs to view this kind of documents, e.g. Adobe original program, but there are many people who like trying new programs which sometimes are even better or faster than the official one. If you want to try a new choice, PDF-XChange Viewer is one of those recommendable choices.
It includes all common functions included in PDF viewers: zoom in and out, rotation, open from URL,... and it is very light, so it runs very well even if your computer is a bit old.
Finally, PDF-XChange Viewer allow you to extract some parts of the document or take snapshots to save them as separate files. With no doubt, it is a very interesting alternative to Adobe Acrobat Reader.