Scottgman said:
I polish my guitars, add fretboard conditioner and adjust intonation every time I change the strings. I tighten up the hardware every now and then. But I'm terrible about wiping down my guitar after playing. My hands get pretty sweaty and I'm sure my strings would last longer if I just wiped down the guitar after playing. 
It is not advised to oil your fingerboard that often. It only really needs to be done about once a year. Any more than that is unlikely to harm anything, but it will not help at all, so why bother.
What we advise you to do, however, is pretty simple. First of all, the best thing you can do for the sound of your guitar is to play it. Something happens when they vibrate, and they get better. This is one of the reasons why most builders HATE selling to collectors. Don't get me wrong, we are willing to sell to them (we have bills to pay, you know), but I hate to find out one of my guitars is not being played, and it does NOT belong in a glass case. There is a reason old guitars sound better than new ones. Lacquer and glue continues to dry, and as the wood vibrates together, it begins to resonate together better. There are people who say they can improve the sound of there guitars by vibrating them with speakers or with vibrators (yes, the kind you buy in the sex shop). They are full of it. The best thing you can do for your guitar is to play it.
Second, when you are done playing, wipe it down. You will keep your guitar clean, and your strings will last longer. The best cloth you will ever find for this, by the way, is an old t-shirt. They are soft, and they have no lint.
Third, change your strings at the very least every two months, and for most people they should do it more often.
Fourth, keep track of your guitars environment. You want to keep the humidity between 40-60%. The temperature should be around 70 degrees. If you need to take it out when the temperature is lower than 50 or so, keep it in the case. Leave it in the case until it comes to room temperature. We get a lot of people coming in complaining about a sort of spider web pattern of cracks in the finish of their guitars, called weather checking. Weather Checking is caused by allowing the temperature of the guitar to come up too fast. The wood expands faster than the lacquer, which causes the cracks.
Lastly, keep an eye on your guitar. Look it over every now and then. Are there any cracks? Does the top have an unusual bulge in it (it is normal for flat top acoustics to have some of what we call behind the bridge bulge, but not too much). Are there any cracks? Do all of the glue joints look solid? When you tap (lightly) on the instrument, does it rattle anywhere? When you play, are there any buzzes, hums, or rattles? Are they localized, or more general? Has the action changed, or the intonation? If any of this has changed, bring it to a good repair shop, and have them look at it. If they are any good, it will not cost anything to get an evaluation and an estimate.
Light
"Cowards can never be moral."
M.K. Gandhi
