To find ILS frequencies:
Press 'M' (default) to bring up the map during a flight.
Find your destination.
You can click the airport, and you'll get all information about tower, ground and ILS frequencies etc. along with runway info.
You'll also see a sort of long, bright green arrow, leading to every runway with ILS. That's the glideslope.
In the runway info, there'll also be a runway heading.
Each runway is named after the closest heading the runway is aligned to. Ie. runway 10 is between heading 95 and 104. Sounds understandable? You then got 10L, 10C and 10R, which is when there are more than one runway 10. That's runway 10Left and 10Right if you got 2, and a 10C if you got three.
Let's say you're landing on runway 10, and the heading in the runway info is 098.
Tune the ILS frequency into the Nav1 or Nav2 radios, and make sure you got the correct instruments set to the Nav radio you decide to use.
Then set your course (in a Cessna ie. you got an instrument called the HSI. With a knob on the right you can manipulate your heading for autopilot uses and stuff, and the one on the left is used for the course. Set the course to 098, and you'll see the yellow arrow in the HSI turn to that heading).
The yellow arrow, as you'll see, is broken. The center piece deviates from left to right, depending on your position. To line up with the runway, you need to center that center-piece. Which is easy, if the piece if on the left of the rest of the arrow, turn left towards the piece, until it centers (you'll need to correct when centered, which is really just turning to the course you've entered). If it's on the right, you turn right towards it.
On each side of the HSI, you'll see a small triangle. These will move up and down, and indicate the glide slope. If the triangles are above the centerlines, you're below the glideslope, and you'll need to even out the plane a bit, until they're centered. If they're below the centerlines, you're above the glide slope, and you need to increase your descent rate a bit, until you're on the glideslope again.
If you got the arrow and the triangles centered, make corrections to heading and descent rate to keep them there.
Before you know it, you'll be right above the runway, at what's called the 'decision height'.
This is a low altitude above the ground, where pilots must decide if there's enough visibility to land, or if they'll have to divert to another airport.
You know what to do from there
That was quite a mouthful, did any of it make sense?
