I like keeping mine wiped down with a silicone cloth for protecting the finish. The idea is to seal the metal off so the air (or dirt or moisture) can't get to it, so whatever you use to oil the moving parts is good enough as long as you keep it applied.

Thanks Kev

+1 on the above advice. silicon rags are worth their weight in gold. i dont know how quickly it evaporates so i wipe mine down every 3-4 weeks. i would guess that high humidity areas might require it more often.

Some Blueing is actually a form of rust. Honest!

Short term storage is OK with a quality gun oil.
See the OM more info on over-oiling.
Avoid multi-pourpose lubes for preservation.
Get a regular gun oil for storage.
Put some on a patch and in the chambers too.

Never use your firearm with oil on it or in the chambers.
Always wipe it down and swab the barrel and chambers first.

For long term storage, a hard neutral wax works much better than oil.

Store in a dry place. Special gun storage bags with desicant inside can help.

I have a re-generatable desicant in my safe. Pop it in the oven for 3 hours when it's saturated, dry it out and good to go. It was 10$ at Cabela's for a 33 cu. ft. jobber.