Caring for Wood  

Depends really....
Oil is good for previously oiled furniture..not that with a varnish or lacquer. Waxes protect bare wood, but also form a protective layer, and a shine to coated furniture.

I'll try wax
Thanks, Robert. I've never used wax, but I'm going to try it. I'm sure this is a very rudimentary subject for most here, but I've only used oil in the past. Thanks.

Careful
I'd be cautious on the wax idea. Depending on the existing finish it can haze and become sticky and hard to remove. Some waxes contain silicone and can form a gritty surface. Paste waxes are OK to use over paint that is old, milk paint or oils, but don't use it on a latex or epoxy paint it'll make a mess! I do agree that oil over a sealed finish like urethane is useless, but in that case I'd recommend using a surface treatment designed to 'refresh' sealants rather than wax. Usually those contain beeswax or citrus oils of some type and can be both shiny or matte to your taste. My Dad, who restores antique clocks swears by: Watco Danish oil with flattening oil to reduce shine for oiled woods, Butcher's paste wax, BriWax and almond oil for other finishes.

Renaissance Wax
I'm considering using Renaissance Wax (see link) described as "semi-synthetic micro-crystalline fossil-origin wax entirely free of damaging acids". I't seems to have a good reputation for wood. None of my pieces is painted, by the way.
http://www.restorationproduct.com/renwaxinfo.html