There’s more to mowing your lawn than just firing up the mower and cutting the grass. As any mechanically inclined person knows, an engine, such as a mower engine needs monthly maintenance.
These monthly duties include checking the oil and refilling when needed, removing any and all debris from underneath the mower deck(remember to do this while the gas tank is empty), check all the cables to ensure they are secure and check the tires and blades to make sure they are tight.
When you are doing the regular monthly maintenance make sure that you take your time and do it correctly. Safety is an issue, be sure to have thick leather work gloves. Also making sure that you have the proper tools for the task at hand is a good idea, you should be able to do this job with a regular ½ wrench or socket and a pair of pliers. These will come in handy in tightening any loose bolts and to properly adjust your cables. You will need some engine oil to top off your oil tank, like any combustion engine, you need oil to make sure your engine does not lock up on you. You can also use the oil for lubricating the wheels and the blades. If you want to get a good even cut, you can remove your blades and sharpen them using a file. If you go this route, be sure to wear gloves to prevent getting cut, even a dull blade can leave a nasty cut. The mower is now ready to cut the grass and tame your wild lawn.
Source of Information on Maintaining your Lawn Mower