I guess you mean something different than the obvious "try it - if it tells you it can't install on this computer, it's the wrong one?"
The restore disks will have an OS X version, and a part number.
Look for one with an OS X version that matches your Mac's original version. That will often get you pretty close, where you might have just two or three to choose from. MacTracker, or some of the Mac history sites can help out with discovering which versions are original to your Mac.