Hey ironraven, I'm from the ice+snow+salt=rust zone as well. Your photo looks depressingly familiar. Been there, man, time and time again.

There's no simple solution. For a complete repair, you ultimately have to sandblast/rebuild (or find parts from an equivalent truck, which is often cheaper and easier).

For now, IMO, there's no reason not to go ahead with the phosphoric acid (naval jelly) on any rust you have exposed. That will convert it, for a time, to a non-rusting form. Aside from that, anything that keeps air and oxygen off will slow it down a little. But rust never sleeps.

If it's a full-size North American truck, built on an actual I-beam frame (as opposed to unibody), there's some rust you can afford to ignore or hide, assuming cosmetics aren't a great concern.