I just bought an SKS.  Its a romanian in very good condition.  All matching numbers, good bore, only a few blemishes in the stock, etc.  I'm going to use this to teach my kids how to shoot with iron sights once they outgrow their bb guns. It's also my first "project gun."  And if they ever confiscate firearms this is going in a hole in the yard coated in axel greese in a PVC tube with a case of wolf ammo.  I'm really pleased with this rifle, it has more character than any of my others.

I disassembled it an noticed a few things.  First, there is a very small amount of fine surface rust in the corners of the receiver, but no pits or anything serious.  Second, the inside of the stock is not coated in whatever was used of the outside of the stock, just bare wood.  Its really dingy in there, kinda like the floor boards in my Dad's barn beneath where the tractor sat for the last 50 years.  

My questions are:

Whats a good way to take care of the little amount of surface rust present?  Will soaking it with WD-40 and swabbing it out work or should I try something else?  I thought of steel wool but am hesitant to use this on the finish.  Any suggestions?

Second, should I coat the inside of the stock or just clean it out and leave it bare wood?  I'm going to cover up the scratches in the outside with a coat of polyurithane.  Was the inside surface left bare for any particular reason other that haste of assembly?

Third, what should I use to grease up the parts before I reassemble it to prevent corrosion? I split my time between Idaho and the coast of Alaska and am worried about the damp salt air.  

Thanks all in advance.  And thanks to those who recommended the rifle on a thread I started a while ago, I'm very pleased with it.

The SKS is a great little reliable, fun, and inexpensive weapon.  I love mine.

To answer your questions, a liberal amount of oil rubbed into the light surface rust should take care of that.  I would not worry about the inside of the stock.  They are typically so rough that finishing it wouldn't really do anything for it.  Sand it down smooth, and you lose the nice receiver fit.  It was intentionally left unfinished=extra cost to finish with no real function.

I don't have to deal with salt air, so I can't really help you there.  I would say just coat everything well with oil and run a dry patch through before firing.  I fire my SKS with the action pretty well lubed.

One last thing.  My four year old shoots my SKS and loves it, recoil and all (mild), but do your kids a favor and break them in on a .22lr first.  Then let them step up when ready.

Another thought about teaching kids marksmanship with the SKS.  Have you fired yours yet?  With Wolf ammo?  Imagine a child's frustration trying to hit the bullseye with a weapon designed for reliability and cheap production, not accuracy.  Now add in cheap Russian surplus ammo.  (Note:  I shoot Wolf too, I just know not to expect .5" groups with it.)  Now throw in on top of all of that the small child anticipating the recoil (OK, more noise than recoil).

Most of all, keep it safe and have fun!

If "they" start confiscating guns, use the SKS to give "them" the whole case of wolf ammo. Don't bury it, bury "them".

If you're really planning on shooting your "new" SKS alot, I would recommend purchasing a cheap plastic stock.  It was the best upgrade for mine.  Maybe the Romanian ones use a longer stock but mine being chinese had a very short stock.  The Butler Creek is no gem, but you're not exactly going to lose accuracy with an SKS either.  Actually the unfinished wood on the inside of the stock only absorbs moisture and could eventually cause even greater rusting than you have now - which CLP should wipe right out.  BTW never use WD-40 on a firearm, not even an SKS.  If you're really attached to the wood stock you can coat the inside with linseed oil for some added protection.  Changing the stock on an SKS is a snap - literally.  Swapping the handguard is the real killer.  It's attached with a pin - of course mine, as are most was ground down after assembly to where you couldn't even see the pin.  After several hit and miss attempts with a punch I got the other side of the pin to protrude enough to outline the hole.  I still had to drill it to get it to move.  Enough rambling, have your kids wear hearing protection, the SKS although not much of a kicker, has a sharp report.

hehehe

Hardwood beat me to the point regarding linseed oil inside the stock.  I did this to my Mosin-Nagant.  I oiled both the outside and inside of the stock.  If you decide to go the oil route, put several, 4 or 5 on.  Especially on the inside, if the wood is that dry it will absorb alot of oil.  Adding the oil should go a long way to help strengthen the wood to.

Have fun with it, I like my SKS better than my AK.  I haven't found accuracy to be all that bad, even with wolf ammo, sure it no tack driver, but it does it's job very well.