Damn, pipped at the post, I'm 80 odd in the post count thing.
Its a shame really, I dont have military experience though I am something of an expert with the weapons of the area, from polearms to battle axes and long swords to daggers. Skill with some melee weapons would be an adviable part of training, just to a basic level, for situations when ammo runs low or if you are caught short escaping a group of enemies. Its important given the numbers of the forces involved that 'we' (since I technically cannot be included...) not loose anyone, we dont have the manpower to be able to afford it.
As for approaches I'd suggest....
1. Clear command structure : this would be the first step before anything else could be accomplished. Leadership and structure are needed, the basic arrangment suggested before seems to be the best one.
2. Establishment of Base : Clearing of the area and recon would be the main steps here, setting up a defendable base of operations is the next step logically speaking. Searching the area, finding out what natural resources we have available to use in the area, sources of water, food etc need to be secured ASAP, then more strategic resources.....
3. Assesment of Options : Based upon the exact rescources of the area, possible strategies could emmerge at this point....as Lord Wong mentioned methanol would be the best source of fuel for vehicles, this would mean agricultural facilities annexed to the base....things of this ilk.
4. Development of supplies : The suggestions of arming up middle earth against Sauron is an admirable one...and an area where some of my skills come into thier own....there is no real hope I would think of use with our varying skills of being able to fabricate modern automatic weapons for full sized armies to face the Dark Lord's minions (though whether its the Dark Lord sauron or our own Dark Lord, Wong in threads like this
...) therefore I'd suggest limited development of grapeshot style cannon weapons for them, nothing too complex a load of explosives, a big metal bowl and a lot of sharp things...a number of weapons like this could slow orc charges. I'd also suggest the use of tight formations and either polearms, or roman style drills to hold the troops together. Possibly deployment of mixed ranks with "blunderbuss" style technology would also be a possibility....before moving out to implement this, we would need to develop the equipment and technology (possibly developing our own training course to run blacksmiths etc and then troops through).
5. Allies : We would need allies, first of all recruiting locals to handle our food production needs and any mining would be a good idea. Once our basic needs are fufilled, alliances for military purposes would take priority. I would suggest an early approach to orthanc...if we arrive that early, then Saruman will not have yet fallen....he could be convinced through a demonstration of technology that he really doesnt want to oppose us, thus eliminating half the problems...then gathering together Gondor and Rohan as the main basis of forces.