From a GM-ing standpoint, it would indeed be helpful to know the general thrust of your plans. The way to the ruins is, according to your native hosts, fairly easy going to start with, as opnce upon a time there used to be a road, which you can see leading into the forest even now. After about 5 mils (I hex of 'trail' movement) it fades out and becomes game trails and suchlike (normal off-trail forest movement). With any significant amount of exploring combined with foot travel, probably need to camp out a bit, but perhaps can get far enough back that you don't have to worry about the restless inhabitants visiting your campsite.
One possibility your host suggests is this. The actual ruins themselves are taboo to the tribe -- only the shaman-priest and magician-priest have the proper spiritual energies to risk exposure to that haunted abode, and they don't choose to do so. Consider the 'hex' containing the ruins to be officially off-limits to tribe members. However, some of the hunters and warriors of the tribe would be willing to escort you to the end of the 'trail' portion of the trip -- one hex to the west, i.e. 5 mils from the village -- and set up a hunting camp there. That way you could bring your mounts that far, and be able to walk the 5 miles to and from the ruins at the beginning and end of each day, and camp' in a pretty darn secure location -- even low level barbarians can be pretty fierce in sufficient numbers, and these guys aren't afraid of a few ogres or a swarm of bakemono or both -- 30 barbarians in a rage can whup up pretty good on random humanoid opponents, especially if some of them are higher than 1st level!
In return for this, they would expect a tithe of random treasure to be given to the village. You would be pretty safe from random night-time encounters, have your mounts taken care of, etc. They aren't looking for a full cut of the magic -- though if you find some minor stuff that they could use, once their shaman 'purified' it, they wouldn't turn it down. But say 10% of the monetary loot would be good, that stuff can get cleaned up by the shaman as well so that it has no lingering curses or whatever -- the villagers may be illiterate and superstitious but they aren't stupid! They can use that to buy stuff from you civilized folks, some of whom aren't into bartering for furs and the like... The Warleader would be in charge of the base camp, and during the day they might detach a hunting party -- say 10 guys each day go out to hunt and forage to supply the camp, rotating out who gets to go and who gets to stay on a given day.
Of course you are welcome to just go out for a while and then come back to stay here at the village, however you want to arrange it. But it IS a long days walk to go out and back in a single day...and there is usually safety in numbers. So if you want their services, they are willing to help out! They just won't be going into the ruins themselves...
Now, once you get to the ruins, the method of exploration is up to you. These ruins are somewhat spread out, so would lend themselves to a 'one area at a time' approach. One GM-friendly approach I might suggest would be to start with the first buildings or whatever you find as you approach from the east, and sort of take bites out of the area as you would from a big cookie -- i.e. rather than go all the way around and then go after outlying buildings at random, that you sort of work your way in from one direction. That way if I fail to fully populate the region I can focus on the stuff you'll be exploring first... And at the same time, it makes a certain amount of sense tactically as well -- if each 'bite' is adjacent to one or more previous bites, so that you essentially establish an ever-increasing radius of explored area without leaving anything unexplored behind you -- kinda like a military beachhead being expanded -- then you only have to worry about what is ahead of you...
But I can adapt to whatever you decide to do, most likely. And I'll try to have the bulk of the place fleshed out -- so to speak -- to start with. Just trying to be realistic and say it may not be 100%... :)
-- Ernie III