I suggest using just a slightly damp cloth or chamois to polish the finish of the guitar body. DO NOT USE A VERY DAMP CLOTH!! Because as water sets it will harm or even warp certain areas.
I've heard of people using a drop or two of Almond oil on the fretboard but I don't know about this. But I suggest using a very fine steel wool and lightly going over the fretboard to remove any oil that might be attributed to sweat.
Every person has their own unique body chemistry and some people sweat more than others. So what I suggest is after each time you play your guitar, you wipe the strings to remove anything that might inhibit oxidation. As in time as strings get old they lose their abilitly to retain intonation and tune. So just get in the habit of wiping . And when your not playing your guitar might I suggest keeping your guitar in it's case. Since this is what is made for and is a lot better than just leaving it propped up in some corner of your house.
Mind you that there are different ways and methods out there for cleaning your guitar and if you are in doubt, contact a professional. They might have some special cleaners out there such as,"Martin Guitar Polish".
Remember, to respect your guitar and it will give you years of music pleasure for you and others.
