If you want to use Tor on your Mac OS X or Linux there is a new bundle you can easy use. The bundle includes all necessary tools and a preconfigured Firefox with the necessary plugin.
Up to now the Tor Browser Bundle is still beta but for me it works without problems. I could post a link here but please download it directly from the Tor website: www.torproject.org and verify the checksum to be sure you got a correct version of the software.
I tested the version on Mac and on Fedora 15. Just extract the downloaded file and run the start script or click on the symbol and everything starts without further user interaction needed. To be sure your identity is safe please read the information here: https://www.torproject.org/download/download.html.en#warning
Maybe you are in the position to support the Tor project by running a relay or a bridge to make the Tor network more powerful and secure for people who need to use this nice tool for uncensored internet access.
Some basic information about running a relay: https://www.torproject.org/docs/tor-doc-relay.html.en