Other items and supplies include a plastic drip tray motor oil and a container for waste oil. Often a large piece of cardboard is useful as well an old rag or cloth. Also know that this guide deals with push or self-propelled mowers not riding mowers. While some advice here applies they are another animal altogether.
In the following guide we mainly focus on walk-behind mowers since the majority of lawns are served perfectly well by these machines. However if you have a lawn that is larger than half an acre you may want a riding mower. If you have a yard that is between a quarter and half an acre consider a self-propelled model. This basically means you do less pushing. Self-propelled mowers are especially helpful on hills. Also pay special attention to blade size. Look for a mower with a blade thats at least 20-inches long if you have a larger yard. Conversely if you have many narrow areas to mow a smaller deck the area within which the blade spins around is best.
To clean it first start with a cool engine. If your mower has a fuel valve switch it off. If you can disconnect the spark plug too. Next use a leaf blower to blast away any old dirt and major debris. Now gently lay the mower on its side fuel cap facing up. Try to get rid of any junk on the mowers underside as well.