Squirrel, you have to lube the string serving some do it every time they put it away, as well some rails have to be lubes. Other than that the strings either have to be replaced or reserved every so often. Bohning makes a good serving kit but you should stretch the string while being reserved. The bohning kit comes with a dvd expaining but you may be able to get instructions online. do not shoot the bow if the serving has worn to a point that the string will touch anything. Get some blue loctite (automotive supply) for any bolts or screw threads that back off.
Don