A few tips:
Some of the rarer skins I managed to find by fast travelling between campsites near the animal in question and circling around with my owl. Keeping your hunter vision on will help you spot rare animal scent trails. If you don't see the beast after a few passes, rest to switch to day/night or fast travel to another camp near the beast and try again. (I also used this tactic to track down some rare tameable beasts).
Clays and reeds are typically nearer water. Probably goes without saying, but resources named North/South are typically found in the North/South of the map respectively.
Also bear in mind that your last two specialists won't appear until you have captured the major Izila/Udam forts, and won't have huts until you complete their initial village missions.
Just keep remembering to skin everything as you go, and pick up every stick and stone you see, and this should come along fairly naturally whilst going for everything else.
List of resources below. Note that you can't deposit items and you can only carry so much, so don't waste time trying to farm all the easy resources early - focus on keeping hold of the skins. You can always run around and top up slate, alder and reeds once everything else is in hand.
Takkar's hut:
Level 1:
4 Alder Wood, 3 Slate, 2 Reeds, 4 Goat Skins
Level 2:
35 Alder Wood, 25 Slate, 10 Reeds, 4 Badger Skins, 40 village population
Sayla's Hut:
Level 1:
4 Alder Wood, 3 Slate, 2 Reeds, 2 Deer Skins
Level 2:
35 Alder Wood, 20 Slate, 20 Reeds, 4 Mammoth Skins, 40 Village population
Tensay's hut:
Level 1:
2 Alder Wood, 2 Slate, 2 Reeds, 2 Wolf Skins
Level 2:
38 Alder Wood, 15 Slate, 16 Reeds, 1 Rare Black Lion Skin, 40 Village population
Wogah's hut:
Level 1:
3 Alder Wood, 3 Slate, 3 Reeds, 2 Jaguar Skins
Level 2:
20 North Cedar, 15 North Black Rock, 10 North Clay, 3 Cave Bear Skins, 40 Village population
Jayma's hut:
Level 1:
5 Alder Wood, 4 Slate, 3 Reeds, 1 Brown Bear Skin
Level 2:
45 South Maple, 30 South Stone, 15 South Rock Dust, 2 Rare White Deer Skins, 40 Village population
Karoosh's hut:
Level 1:
4 Alder Wood, 5 Slate, 2 Reeds, 4 Wolf Skins
Level 2:
30 North Cedar, 35 North Black Rock, 20 North Clay, 1 Rare Stripe Wolf Skin, 40 Village population
Dah's hut:
Level 1:
15 North Cedar, 15 North Black Rock, 15 North Clay, 1 Rare Black Dhole Skin, 40 Village population
Level 2:
35 North Cedar, 25 North Black Rock, 20 North Clay, 1 Rare Two Horn Rhino Skin, 50 Village population
Roshani's hut
Level 1:
25 South Maple, 20 South Stone, 15 South Rock Dust, 2 Rare Red Elk Skins, 40 Village population
Level 2:
50 South Maple, 40 South Stone, 30 South Rock Dust, 2 Rare Red Bitefish Skins, 50 Village population
Any mistakes spotted or tips to add, let me know in the comments.