Follow the directions on the Adobe site to download and install the Acrobat Reader on to your computer. 

How this will work
When installed on your computer, Adobe Reader will open automatically when a  link to a .pdf file is clicked.

To save a .pdf document onto your PC, just click on the "File" menu on the top toolbar and selecting "Save as". You can also click the print button and print the .pdf document out. If you have typed onto the .pdf file you will not be allowed to save it, only print it.

Further information about .pdf files and Adobe
The Portable Document Format (.pdf file) was created by the software and publishing tools company, Adobe, to allow people to view and print a file exactly as the author intended it to be, meaning that the format and fonts remain consistent for all viewers across most all platforms. For more detailed information, visit Adobe's Reader Information page.