Thanks for the input.

I guess I should have been more specific about what is going on. Sorry, my bad

The wheel in question is a front wheel. Age is about 6-8 years old. I noticed recently when I was pedeling hard there was a slight "pinging" noise coming from one of the wheels. Naturally, I assumed it was caused by a spoke so I began squeezing each pair of spokes until I found the culprit. A spoke had come loose. So loose that it was almost falling away from the nipple.

I put the wheel in my truing stand and tightened the offending nipple/spoke by hand, then with a spoke wrench, to a tension similar to the spoke crossing it. Then I went back, trued the wheel and checked the alignment with a dishing gauge. The wheel seems fine now, but when I tap on the spokes the pitch varies a bit from pair to pair, as does the tension when I squeeze them.

I decided to take a look at the rear wheel and when I squeezed each pair of spokes they seemed to be a bit loose over all (at least in comparison to some other wheels I have laying around the garage). Yes, the drive-side spokes are tighter than the non-drive side.

So I guess my question is: How do I know what the proper tension for spokes is? How tight should I have them? How tight is too tight?

Thanks.