First you need to turn on the battery by rotating the knob to line up with the green mark.  Then to power the pilot's and co-pilot's essential flight instruments you rotate those two knobs to the green lines to receive battery power.  Note:  despite its complex appearance, the yellow, red, and green lines painted on the flight engineer's panel are quite helpful and logical.  Green is the battery power.  Yellow is the generator power flows.  And red is the fuel flow paths.  The knobs are rotated to line up or block off these flow paths as you desire.

OK, after you have the battery powered up, then set the parking brake and turn on the GTC.  The GTC (called an APU in the C-130H model aircraft) is essentially a small turbine engine designed to produce electrical power and compressed air.  The compressed air is used to power up the turbines for engine startup.  To turn on the GTC you first open up the GTC door.  Then you rotate the knob to the start position and then let it go to the run position.  You will wait for the yellow/orange light to illuminate indicating start up and then wait for that light to extinquish which indicates the start up is complete.  Then, flip the switch immediately to the right to bring the GTC turbine up to speed.  Then wait for the green light which indicates the GTC turbines are rotating at proper speed and thus producing proper power and bleed air.

Then, flip the switch to open up the GTC bleed air port.

Then, flip each of the switches below that one to open up the bleed air ports to each of the four engines (note: in the virtual aircraft this is the default setting -- just make sure each of those switches are turned to the on position else no bleed air will get to the turbines and the engines will not start up).  You can also elect to do this in sequence with each engine started or do them all at once.  Does not matter in the virtual aircraft as I have observed.

Push each of the prop condition levers to the full forward position.  You want to start the engines with the props in full RPM setting.   (Likewise to shut down the engines while in flight or on the ground rotate the prop lever ful aft to the feather position.  This shuts down the engine as it feathers the prop.)  Then line up all the throttle levers to the ground idle values.  Be sure you are NOT in the reverse zone.

After this you locate each of the large red round disk-shaped push buttons located just above the aircraft commander's head.  These are the starters in sequence left to right for engines 1, 2, 3, and 4.  In actual C-130 operations we normally elected to first start engine number three because it allowed a ground crew member to unplug and remove the external power cart if we elected to power up the navigational instruments like the INU's and GPS.  The battery could not produce enough power to power up all these extra instruments.

The power cart was connected on the left side of the aircraft, so starting the number three engine first allowed the flight engineer to get that generator fully on line to produce the power to keep all the instruments powered up.  After the generator was online the ground crew would disconnect and remove the power cart.  But, for the virtual aircraft you use the battery for primary flight instrument power and the GTC for bleed air, so it doesn't matter what engine you start first.

To initiate the starter, you briefly mouse over the start button and click and release the left mouse button to cycle it.  On the actual C-130's the pilot would press down and hold the starter until a parallel indicator light illuminated and fuel flow, torque, and TIT was indicated.  But I have found in the virtual aircraft that if you hold down the starter it just cycles the starter igniters without actually turning the turbines.  So, just do a quick cycle -- just one brief left mouse button click.

In the virtual aircraft the response time is quicker than in real life.  However, you will see a surge in torque (again not realistic but a common problem with all turbine engines in the FS series due entirely to code limitations in the primary game code).  Wait for the torque to settle back down to the proper idle setting.  

Once you verify proper ground idle power values on the engine instruments, then rotate the associated generator knob to the on position.  In vers 1.0 you had to first cycle the knob to the re-set position.  This was not realistic and vers 1.1 fixed this issue.  (However, I have noted that the number two generator does not show a power indication.  That is a bug I have reported.)  For the other engines (1, 3, and 4) once you have the engine powered up in ground idle and rotate the generator knob to the on position, you will see the power needle move to a powered state.

Once you have at least one generator on line and power flow indication on the needle, then you can switch from battery power to main DC power.  First, turn the ATM power knob to the re-set position and then to the on position.  You will see the ATM needle power up at this point.  Then, to the 4 o'clock of this you will see the power bus knobs.  One allows you to select main or essential power modes of operation.  You want to select the main power option.  The essential DC is designed to provide emergency power to essential flight instruments only.  This is selected only when you have a generator failure and are concerned about minimizing total power draw.

Now reference the pilot and co-pilot instrument power knobs and rotate them to line up with the yellow line.  This powers these flight instruments off the generator vice the battery.  To the left of these knobs is another knob (sorry name escapes me at the moment -- shame on me!) and you rotate this to also line up with the generator power yellow line.

At this point, you can rotate the battery knob to the recharge position, which is full left and aligned with the upper green line.  This setting allows the generator power to recharge the battery during flight.  

Now repeat the start up sequence for the remaining engines and bring each associated generator online.  From this point forward the C-130 have four independently running generators each able to singularly power all required instrumentation provided the associated engine is not in low speed ground idle.  Those are the little green disk-shaped buttons you push down and are located on the center console just left of the co-pilot.  These are pressed down to engage the engine in low-speed ground idle.  It helps preserve fuel and minimize engine wear and tear.  But remember, at least in the real aircraft, it also robs generator power so you must have at least one engine on speed or a ground power cart connected.

This tutorial works for me: http://www.fsstation.com/tutorials/legendaryc130.html