How to care for the finish of your guitar:

A clean lint-free cotton cloth is best to wipe your guitar off. If there is an area which will not come clean, moisten the cloth a little with water. Polish should be used only if the damp cloth doesn't work. We recommend Martin Guitar Polish. Be careful when using polish, it could get in the cracks and make a mess of the wood. Never use paper towels for the same reason.

Baby Your Guitar With The Right Polishing Cloth.
DO NOT USE “Special Polishing Cloths” for your guitar. The best (and cheapest) polishing cloth is CLOTH BABY DIAPERS. One pack of cloth diapers should last you for years. Make sure they're 100% cotton.

Storing your guitar:

The best place to keep your guitar is in its case. Your case will insulate the guitar from rapid changes in humidity and temperature and from physical damage.

If you want to leave it on a stand, do the following...
1.) Keep the sun away from it; NEVER display your guitar anywhere that will be exposed to the sun. 2.) Keep the temperature of the room around 65-80 deg. F.                                             

3.) The humidity of the room at 40%-50%.
3.) Make sure it's in a safe place where someone won't accidentally bump it over.
4.) Dust it periodically.

The best way for you to protect your guitar from damage is to understand what factors affect it and how to control these factors.

Temperature Damage:

High temperatures above 100 degrees will cause glue joint failure and softening of the lacquer, making it susceptible to damage. Temperatures below freezing will cause lacquer to craze and check. Rapid changes will cause worse damage than if the changes take place slowly and the instrument has plenty of time to acclimate.

Direct sunlight is will soften the glue in your acoustic guitar, which will weaken or destroy the joints. Do not display your guitar anywhere that will be exposed to the sun. Be careful if you perform outside on nice sunny days; try to be in a shaded area.

Humidity Damage:

Understanding the effects that temperature and humidity have on solid wood are the most important factors to protecting and prolonging the life of your acoustic guitar.  In general, the conditions we ourselves find comfortable are also the best conditions for a solid wood instrument. We recommend that you buy a digital hygrometer and sensitize yourself to the conditions required to protect your acoustic guitar. A hygrometer measures the amount of Relative Humidity (RH), in the air.

Low Humidity Conditions:

The effects of heating, especially when using wood or electric methods of heating further dries out the air; you will have to be careful to protect your guitar from low humidity damage. If you generally keep your guitar inside your house and prefer to keep it out of the case, you should have a room humidified to 47%, and a hygrometer monitoring the RH of the room. If you live in a hot but dry area, you might consider using a swamp cooler instead of air-conditioning. This will add humidity to your environment.  Low Humidity, can cause cracking in both the wood and lacquer. The top will drop, lowering action sometimes to the degree that your guitar will become unplayable. Lacquer checks will develop along the bindings and seams. The fingerboard will shrink. This will make your guitar uncomfortable to play.

High Humidity Conditions:

High humidity is harder to deal with, but it is also is a safer condition. Air conditioning will really help you keep the humidity at a reasonable level. High humidity, 65% and above, causes the top to rise, making your guitar unplayable. It can cause lacquer to check, impressions of the bracing may appear on the top, and puck marks may appear where the top is glued to the internal structure of the guitar, such as at bridges, braces, head blocks, and tail blocks. It will restrict movement of the top making your guitar sound tight or restricted.

Rapid Changes:

Rapid changing humidity is the most damaging condition you can expose your guitar to. Having a guitar go from an environment of 85% humidity to 35% immediately could cause severe damage. Your case is your best tool for insulating your guitar from extreme conditions and rapid changes in conditions.

Stabilization:

Humidity is most damaging during the first 5 years of your guitar’s life. If your guitar has been well controlled and stabilized during that time then it is far less likely to ever have problems. Most vintage instruments are less likely to react to humidity changes unlike a new guitar would.