Some people find mowing their grass tedious whilst others find it therapeutic and satisfying. Whichever group you subscribe to, having the right mower for the job will make it much easier.
There are basically two types of lawnmower. A cylinder mower which is exactly what it says, it has blades on a cylinder. It also usually has a roller either in front of the blades or behind. This is what gives you the stripes when you regularly mow your lawn in the same way. A cylinder mower will generally give you a much better finish than a rotary mower. You should try to get as many blades on the cylinder as possible. A collector box for the cut grass is also useful since this helps to prevent thatch accumulating.
A rotary lawnmower is once again exactly what it says. The blades are mounted in a circle and turn round fast to cut the grass. Sometimes the blades are replaceable and made of plastic (as in the hovermower) and sometimes they are metal and are capable of being sharpened. The useful thing about a rotary grass mower is that it will cut tall grass. You can use them on close cut lawns but they do not give the same fine finish.
You can buy petrol or electric powered lawnmowers. Some petrol-powered mowers even have electric starters, rather then the string pull which can be hard to master. Electric lawnmowers are generally cheaper to buy than their petrol-powered cousins but have the down side that you are limited to the length of their cable and you must be careful not to cut it. They are, however, generally much lighter than petrol-powered mowers as you are not carrying petrol around with you.