First download the Drivers and install the libusb filter driver using the included application that will do it for you.
Extract the ps3sixaxis_en.exe file to your desktop.
Download the game profiler and install it.
Plug in your sixaxis and double click on the exe file that you extracted then press the PS button.
Start the game profiler.
Go through the initial setup. When you get to the point where you see both you joysticks on the screen with the buttons on the side, move them around and press the buttons. If you installed the filter driver successfully and initiated the exe file then you should see the buttons and joysticks register. If not just execute the the exe file again and press the PS button.
Now when you are at the window where it says play and close on the top right hand corner, click on game profiles.
Select edit configuration on the bottom.
This is where you register your buttons to your Sixaxis. Press any button on your controller and you will see a little menu pop up on the number the button is assigned to. Select "Set Quick Assignment" and then press the letter or symbol you want that button to profile. For Ex., in an NES emulator I want the letters "A" and "B" on the old controller to be "X" and "Square". So I press x and select "Set Quick Assignment". Now I just press "A" on my keyboard and it will show that x will be "A". I do this for the next letter too. Make sure the letters match up with the input configurations in the emulator or it won't work.
After that select save and close. Say ok on the next window.
There you have it... you can now go on an emulator and play with the Sixaxis. You also have the choice to map the buttons on the Sixaxis to the buttons of a mouse. Also you can map the analog sticks to a mouse so that you can use it as a mouse... pretty cool, eh?