where do i add the Scenery once i have downloaded it from the internet
It depends on the type.
If it is mesh, then go to:
C:\Program Files\Microsoft Games\Flight Simulator 9\Scenery
...and paste the .bgl files into the correct location, i.e. mesh for China goes in the Asia folder etc.
You then just need to load the sim and you should have enhanced scenery.
If it is airport scenery etc then go to:
C:\Program Files\Microsoft Games\Flight Simulator 9\Addon Scenery
...and paste the whole folder in there. This folder will contain a sub-folder with 'scenery' and 'textures'. You then need to start FS2004 going to 'Settings' and then 'Scenery' and click 'Add Area' and then choose the name of the file you just pasted into the Addon Scenery folder. Click ok, and you must then restart the sim for the scenery to work.
Very nice explanation there Jon