I hope the person who e-mailed me this morning doesn't mind me posting the response i sent him:
Getting the gauges right...I used something that is probably a bit to expensive solely to get your gauges right. I used a datalogger from pocketlogger.com. It's a good investment if you plan to tune your car with an SAFC, what it's really for. I had it for my previous car. Anyway, it lets you see various parameters of your car. Including speed and rpms. So i basically put my car on cruise control at 40 mph and stuck the needles on. Even this way will take acouple of tries. Plus, be careful, use a back road, etc, etc, etc. You don't want to wreak your car calibrating your needles, or possibly hurt or kill yourself.
A way i've done it in the past before i had my logger. With the tach...Just rev your car to the redline and stick it on at the rev limiter. Your neighbors will hate you but it works. Again, it might take accouple tries. Just make sure that it hits the redline but also the idle is right. You can do the reverse too and set it at idle, then see if it hits the rev limiter right. This should get you close enough to where you are within 100 rpm or so. Plus you can do it in your driveway or a parking lot.
Then for the speedo, this is hard to get perfect with no logger. I've only gotten close, within 2-3mph. I write down before hand what speed i'm going in a certain gear at a certain rpm. I can let you know if you have a 5spd, if you are auto, it's going to be different. Just ask on a forum. Then, if you have any of those signs around town with radar that tell you your speed, drive by one and compare. The one thing they are good for. Not really the best way to do it though, a logger is much better.
Anyway, I really recommend you get a datalogger if you can afford it. It's going to be easy and you have a quick reference you know is right. If you plan on tuning your car, it's a valuable instrument. It will also tell you check engine codes on any OBDII cars which can actually make it's money back compared to taking it to the dealer or somewhere to check the code. Unfortuanately, it's $125 not including the cost of a palm pilot to go alot with it.