Hi there ace !

Do you know how to tune nav1 and use the ILS system in FS04 ?

ATC will guide you to within 30 degrees ( I think ) of the ILS beam.
If there isnt one then ATC will guide you exactly onto the runway.

There is also the option of asking for airport direction if you feel lost.

Yeah back to school you go! 

ILS is very easy, and can help you make a beautiful landing in any weather.

It is explained very well in the FS lessons and the help center thingy.

And a something that often happens to the best of virtual pilots is forgetting to swap the frequencies after you have set it correctly, and then to press the nav1 button to activate it.

There is no way for you to choose, but ATC will guide you to the runway if the airport does not have an ILS.

If it does, ATC will only guide you to the ILS beam and not the runway itself.

( I can see staiduk's post while replying )

Sorry Bro I dont understand all this VOR1 stuff can you teach me please ??  ???

rgr that bro i will pay a visit to the learning center. is COM1 same as VOR1. And is COM2 same as VOR2

Your VOR2 gauge (VOR) will get you to the airport from a
distance of about 180 nm. It will not lline u up with
the rwy heading. Your Vor1 gauge (ILS) is the one which will line u up with the rwy from a distance of aprox 27 nm.
To be realistic go to the fs9 map prior to takeoff and find your destination. Write down all the info.
Load the VOR2 info given into your VOR2 nav system.
Load the VOR1 info given into your VOR1 nav system and
adjust the COURSE hdg on your Autopilot to agree with
the chosen runway heading. When u pick up NAV2 at
about 180nm adjust your hdg to port or starboard to
roughly guarantee that when you get closer you'll be
roughly lined up with the rwy.  At 27nm u'll pick up the
ILS signal. You can fly the plane in manually by watching
the OBS1 gauge and making constant corrections or
much easier, on your autopilot switch off altitude and
indicated air speed and switch from HDG to APP. This
way your place will fly straight in and you can finish
your beer with only altitude to worry about. Shut down
the AP completly at 1 or 2 nms from the rwy.
Cheers / NEK

Ain't we got fun!
The localizer is sensitive; check out those green feathers on the map, which represent the area your instrument will register. Outside that zone the needle will be full over right or left and you will have no idea how much right or left you need to go. To learn this you need VOR 2 (or ADF, if you are landing at KCMH).
When an airport has a regular VOR you can tell what angle you are from that station(they like to place them at the ends of runways), and if you keep the needle at nine o'clock you can fly a circle till you reach your approach heading. Since you already know the direction of the runway (runway number times 10), you can tell when you are ABOUT to intersect the localizer and start your turn to final BEFORE THE NEEDLE STARTS TO MOVE so you won't overshoot it too badly. You want to do this at least ten miles out, at an altitude less than the glideslope and greater than the ground. If you are in a jet give it twenty miles; you can't even see the airport at that distance but jets turn slow, and even prop planes have a tough time catching the localizer if they have more than 45 degrees to turn once the needle starts to move. This is why we have two radios: you can't find the localizer without NAV 2 or ADF, unless you can actually see the airport, and then you are too damned close to fly the pattern unless you are Captain Eddy or something.
If this is too much for you, you can use the GPS to locate the localizer: just aim for the end of the feather and when you reach it turn most of the way towards it and wait for the needle to move.
Adjust the heading knob so the red indicator points towards your approach heading; it helps to have something concrete to look at; and remember to press D to adjust your heading gyro. Turn off the wind the first few times you try this, and put in a lot of fog so you won't be distracted by actually seeing something.