Now that we know what the ILS does, lets solve the question in your heads, how do I get to use this.

The gauge that tells us our ILs info is the one to the right. You will find it in a Cessna on the instrument panel. You will probably find one on any instrument panel, probably looking slightly different.

From that image above you can see the obvious compass on the outside, ignore that for ILS, you don't need it. If however you look in the middle you can see 2 crosses. 1 Cross is made up of 2 dotted lines (and is a perfect cross), these 2 lines never move, these lines just tell you 2 things, (i)It tells you where the centerline is. The idea behind this is that you know where the centerline is (ii) It also tells you the perfect height that the plane should be at. The idea behind this is that it allows you to land at the right place on the runway.

The other cross with the 2 solid lines move (which is why they look crocked), and these 2 lines tell us information. These 2 lines tell us where our plane is. All we have to do is look at the Vor 1 indicator, and decide where our plane is, compared to the perfect center line and perfect altitude. Then we have to act on this, for example if where the 2 solid lines cross is too much to the right of where the 2 dashed lined cross, then we must not be on the centerline. To counter act this, we must turn left slightly until the 2 solid lines cover the 2 dashed lines.

Above is 3 more pictures from ILs landings. In these VORs displays the ILs frequency has been tuned (With the radio. This will be studied later) to the right runway, and I am coming down for a landing. Those 2 solid lines tell me where I am compared with the runway. The solid line going sideways(horizontal) tells us if we are too high or low. If we were to be too low that horizontal solid line would be in the upper part. You must follow the cross of the two solid lines. If that cross moves to the right beyond the vertical dotted line, you too must turn right until the solid line crosses and covers the dotted line.

If I was too high, that solid line cross would be below the dotted horizontal line. What you need to think of is, "I  need to aim for the solid line cross like it was my artificial horizon". Look at the pic 2 of the Vor, in this picture I am too low, and need to go up as that line tells me. I am also a bit off the runway center line, I would need to turn right a bit until that vertical line covers the dotted vertical line.

So do you sort of understand how to read the ILs? Hopefully the answers is yes.

Example Vor display 3 (the one on the left), my Vor indicator tells me I am too low and too much to the right.

In Vor display 2 (the image on the right), my Vor indicator tells me that I am too low and a bit to the left of the runway centerline.

You should treat this as a game, you want to cover up those dotted lines, like the picture on the left. In this case you are lined up for runway and you are at the right height (If you want to talk like a pro, call height altitude).

I would advise you to look at the cool pics section. From there you will be able to see what a good approach looks like, with the ILs.