I did a lot of research on the net looking for the answer to the question; Do I use game pads or a keyboard for the controls? After reading about people having troubles with multiple key press issues, I was very weary of using a keyboard. Many people have used the keyboard interface from Hagstrom electronics, and I don't remember reading any complaints about it, but I just didn't feel it was worth the risk. Now because I planned on running the emulators in Windows exclusively anyways, I decided to use Microsoft Game pads. I had two of them sitting around collecting dust, and they were exactly what I needed. They have 14 buttons each (including directionals) and they can even be hooked together which makes having two joysticks very easy to set up (no need for a y-cable).  Mame32 has full support for all of the buttons on the game pads also, so MS sidewinders are a good solution for Mame32 users.

  I opened up the sidewinders and discarded the plastic casings. Then is just a matter of soldering to all of the proper leads for the directionals, and one wire to the common ground. I attached the sidewinders to the bottom of my control panel, and used connect strips from radio shack to make it easy to connect the game pads to the switches.   I dry fitted all of the buttons and joysticks. Then I chained all of the grounds together and connected it to the ground on the game pad through the connect strip. Then I just wired every switch one by one to the connect strip. Its a long process, but worth the effort.

  Here's a diagram I made to help you understand how to connect the common ground from the gamepad to the control panel, and how you can just chain all of the grounds together on the control panel.

  After the grounds are all linked, its just a matter of connecting each button on the control panel to the appropriate button on the gamepad (the red leads in the diagram).  Here are some shots of the finished wiring.

Here's the Bottom Half...