Spoke noise is ususally a clicking sound, but I suppose you could get some creak. The best thing to do is to ckean your wheel and spokes with mild soap and water. Dry. The noise is almost certainly coming from the cross-lacing or the nipples and eyelets. In the latter case [which is more common], the nipples make a "tinking" noise when your weight compresses the wheel.
So... for the nipples/eyelets... Apply a drop of double-boiled linseed oil to each nipple so that it oozes slightly into the eyelets.
For the cross-lacing, apply a drop of linseed oil to each cross.
That should solve your problem.