jonreading

For me...

Sand to remove the finish (usually a water-based acrylic) and splinters. I prefer Linseed oil; old-skool is to cut the linseed oil with mineral spirits for the first several applications to improve the penetration in to the wood. Wait 30 minutes after application and wipe excess. You should not let either tung or linseed oil set up on the wood, this will leave a sap-like tacky residue. The heavier oils will have better preservative features (hence why linseed oil is still the favorite of gardeners for wooden tools). Some places do not recommend sanding as it can clog pores in the wood, especially if you use old paper and sand for a prolonged period of time. Unfortunately, most of us do not have fancy tools to plane the wood instead of sanding. General rule of thumb for me is periodic sanding and oiling when the wood feels "dry", roughly every 3-6 months.

As for storage... living conditions storage is best (comfortable temperature and medium-low humidity). Avoid extreme temperature (heat or cold) and extreme humidity. Vertical storage is fine in ideal conditions, but horizontal is better if the weapons are exposed to fluctuating temperature or humidity.