Re: Surface rust....at least I hope it's just surface
For <span style="font-style: italic">removing</span> the rust, use steel wool and any light oil you wish - RemOil, WD40, whatever. The type of oil doesn't matter for this step.
For <span style="font-style: italic">preventing</span> rust in excessively humid environments, you want something thick. RemOil and the like doesn't cut it, in my experience. I've been spraying down the machine tools in my shop with PB Blaster Corrosion Stop, which is fairly sticky stuff. Boeshield also works well.