In a separate page, I lay out position and speed. Then you need a script to set the flaps, landing gear, and a few other settings that can't otherwise be set.
In Windows 7, put the script in C:\Users\<user>\AppData\Roaming\flightgear.org\Nasal. Make sure it has a *.nas extension, and that it's the only .nas extension. If you have other scripts, you can rename them to ".not" or such.
This script is a variation of my landing drill scripts.