Well, I don't know how to make an approach.

I know how to start the plane, take off, follow the waypoints with VNAV and LNAV.

Could someone explain how to pilot the plane from the top of descent to the touchdown ?

When must I press on "SPD" ?
Why do we have to enter the altitude in the glareshield , enven if it is written in the legs page of the FMS ?

Could someone make a little tutorial about how to make a good approach and landing ?
That would help me a lot, and I guess that I'm not the only one !

(It can be a tutorial with text only, or text + screenshots (better) or even a video)

Please, help me , my passengers will panic if the learn that I don't know how to land correctly ! ::)