"offset"

When referring to wheels, what does the word "offset" mean? I've noticed this number is usually around 42mm.

Offset is a number referring to how many millimeters the center of the rim is from the mounting surface of the axle. For instance, a +42mm offset means that the axle and wheel meet 42mm OUTSIDE (away from the car) the center of the rim.

I never knew what it meant, only to get the same when buying rims, but..

offset is basically how far the holes are from the center of the rim?

No, that's the bolt circle. The offset is how far your wheel will stick out of the wheel well, or how far it will sit inside the wheel well. The higher the offset, the further into the wheel well the rim will be.

Oh I see what you're talking about. So does that mean that offset doesn't really matter as long as its above a certain number where it would be sticking out of the wheel well?

An offset of 42mm is a pretty high offset. If you have a lower offset than that, it will stick more out of the wheel well. If the eclipse was designed for a 42mm offset and you put a wheel with a 32mm offset on it, then that wheel will stick out 10mm more than stock. You generally want to stay with stock or +/- 5-10 mm on the offset, because it can put undue stress on the axles, rub the fender wells, and/or adversely effect handling. But by getting the correct offset, you will have good handling, and the axles won't be overly stressed.

so whats the idea size of rims that one should get for a Talon / Eclipse ???
17's or 18's
this is for a car that leans toward go more then show ???

smaller rim size is better for racing, and are lighter (generally) because of that. Lots of fast DSM's use 16's, but i'm sure 17's aren't that bad either.

16s are commonly use din drag racing because a bigger sidewall absorbs some shock on the launch and keeps yo from breaking traction for a bit longer. I have no trouble getting 1.6s and the occasional 1.5 on 50 series 17s though. For show, I think you would be running 17s at the smallest. Most would go 18s on a dSM. Bigger than that and you have to really plan accordingly. PEople run them, but its not as simple as just buyng them and tossing them on from what I hear ;) We dont have much room in the wheel wells and to the suspension.