Amateur technical stuff on building it

I was just thinking, what kind of skills do you need in order to build a MAME cabinet? Well, for starters, don't let inexperience scare you off. I'm not embarrassed to say that I'm pretty light-on for technical skills. My talents lie elsewhere (wherever that may be) but I don't consider myself an idiot. If you can't do simple maths or follow wires then perhaps this isn't the project for you. However, common sense and some idea of how things work will see you through.
I can only speak from modifying an existing cabinet. Seeing as my woodworking skills are pretty crap, I wasn't interested in building my own from scratch (although with plans I can't imagine this would be too hard - all the cuts are straight lines.) For starters you are going to need some basic tools. Luckily my housemate has a hammer and drill but I keep meaning to buy my own drill anyway. I had a rotary tool (sometimes called a Dremel, although mine's a Ryobi), screwdrivers, shifters, a soldering iron and a borrowed jig-saw. That's about it really.
Research - I can't stress this enough. I spent a good month or so scouring the web for information on what I needed. And take lots of notes. When I unplugged the monitor and pulled it out of the cabinet I made damn sure I knew how it went back in and what plugged in where. It was several months before it went back in and I had long forgotten which way up some of the plugs went. My notebook and digital camera were a HUGE help.

The rotary tool is a pretty cool item. Like a power drill but smaller, it is ideal for sanding back tiny bits of stuff or polishing the burrs off bits of steel you just drilled or cut. I've used mine extensively on this project and love it - almost a must-have item.
A soldering iron you could possibly get away without, but if you are making any alterations to the electrical/power system then you will need one. Also, make sure you put heatshrink over any of the bare wires you end up with when you work on the higher voltage lines. You don't want those things shorting out onto each other or you! Heatshrink is that soft plastic tubing you can buy that shrinks when heated. You simply cut a short length of it, slide it over the wire and then solder the wire where you need it. Slide the heatshrink down over the bit you just soldered and briefly run the flame from a cigarette lighter over the tubing. It will shrink and seal over the bare wiring leaving everything neat, safe, and professional-looking. Buy a few different widths to cater for different wire and connector thicknesses.

Oh yeah, another thing you'll need is a crimping tool and some quick disconnects (QDs) - they are also called quick connectors. Here you can see my MCA-style joystick with a QD stuck on one of the microswitch lugs. Below that you can see a bare microswitch with a QD on it and at the bottom is the QD by itself. The ones that fit on a microswitch are female red spade connectors that are 6.4mm or so across. Jaycar sell them in packets of 100 (or 8, but you'll need way more than that) and here's a LINK TO THEM. You could go crazy and also buy piggyback versions to run your ground loop but I wouldn't bother, just crimp two wires into the one connector instead.
Here's my cheap and nasty crimping tool. It came in one of those super-cheap automotive toolkits that have a heap of tools for A$30 or so. You know they are all crappy quality but who really cares. I've no idea if my crimper is shoddy or not, but it seems to do the job. Feel free to use the demonstrated pliers instead. I haven't, but I imagine they do just as good a job.
So, you just bare the end off a wire and stick it in the red end of the connector. Stop before it pokes out the other end and crimp that sucker down. Do it a couple of times and tug on the wire to make sure it's snug.
Why do this? Well, it makes it far easier to change controls if you don't have to desolder everything. Trust me on this.

NOTE: I am NOT an electrician. Don't think that I know what I'm talking about when it comes to electricity. I like to think I know what I'm doing but I'm NOT qualified in any way. Reproduce my work AT YOUR OWN RISK.