Tips for taking care of your guitar (cleaning, storage, string replacement).
It is easy to damage a guitar by accidently knocking it over. So when you are not playing your guitar, it is a good idea to put it in a safe place where it will not accidently get kicked, sat upon, stepped on or knocked over. When you are not playing our guitar, you should keep it in its case or on a guitar stand. You should always be careful handling you guitar--don’t bang it into anything; handle it. When you are carrying your guitar, you should hold it around the neck next to the heel (by the body of the guitar).
You should also avoid leaving your guitar in places that are not climate controlled; if there is a sudden change in temperature or humidity, you guitar may get damaged. You should never leave it by an air-conditioning/heating outlet, a radiator, or in the sun. Too much heat or extreme dryness may cause your guitar to crack or split. On the other hand, too much humidity or extreme cold may cause the glues on your guitar to soften. If you live in an extremely hot or dry climate, you may consider investing in a guitar humidifier which you should place in your guitar case along with your guitar when you are not using it.
To clean your guitar, you should take a soft cloth and wipe off your entire guitar when you are finished playing. If you want your strings to last longer, you can take the same cloth and carefully wipe each string to remove dirt and sweat. You may also want to polish your guitar with guitar polish once or twice a year (if it has a lacquer finish). If you choose to do this, you should avoid using silicon-based polishes as they will leave a permanent coating on the guitar which may get in the way if you have to make repairs later.
You should replace the strings on your guitar every three months (at the very least). You should also replace *all* of your strings if a string breaks or if the strings sound dead or are worn out.
As far as travelling with your guitar goes, it is best to keep your guitar in a hard case. If you do not have a car, lay your guitar on its back somewhere where it will not slide around much (eg. the trunk of your car). Make sure the neck and head of the guitar will not be strained or knocked about. If you plan on flying with your guitar, a hard case is almost a necessity. You should loosely pad the inside of your case to make sure the guitar won't be easily jarred, and you should be sure to label your case "fragile".