Below are links to some free, usefull stuff to download.
(We recommend you get an Apple Mac computer if you don't have one)

http://www.opensourcemac.org
(Best of the best free, opensource applications for Mac OS X)

http://www.freemacware.com
(Lots and lots of free applications for Mac OS X)

Get Adobe's free PDF reader (45Mb)
The original and most complete PDF reader.

Get Foxit's free PDF reader (6Mb)
Much smaller (hence quicker) to download.