1) go to http://folding.stanford.edu
2) Click on "Downloads"
3) Download the appropriate Operating System client. If this is your first time, I reccommend the graphical client
4) Install it (duh)
5) When you first run it, pick a unique username (so you aren't folding for someone else) and set the team to 11108
6) Add it to your startup folder (If you run windows. I'm *nix-dumb)
7) ADVANCED OPTION: Edit the startup shortcut to use the command-line arguments "-forcesse -advmethods -verbosity 9"
Let your computer run 24/7
9) Lather, Rinse, and Repeat on whatever computers you can get your hands on! (With permission, of course)