The picture above is of the setup i use to test.
All the servo input signal wires are connected to the same row on the breadboard. and connected to ground
the Servo tester is pluged into the control channel to pick MANUAL, FBW and AUTO
The green cable is just to power the board, pulling from vcc on the FTDI and into VCC on the header next to the ftdi. also my ftdi is a 3.3v, but 5v will work just the same.
You must also modify the current SVN code - inside radio.pde
here is what i changed - change to a comment timer(1-3)diff
//Filter Radio input
// timer1diff -= 46;
ch1_temp = timer1diff * .5;
// timer2diff -= 38;
ch2_temp = timer2diff * .5;
// timer3diff += 10;
ch3_raw = timer3diff * .5;
What this code change does is make it so it does not change the time into the 32000's as - 46 from 0 on an unsigned int is large.
The rest is standard software setup. goto http://code.google.com/p/ardupilot/wiki/FlightSim to do your own.