In your camping area you have(In multiplayer at least...):




-6 traps
-2 guns
-3 packs of ammo
-12 flares (3 flare guns also)
-2 medkits
-etc. stuff that always spawns (I didn't include what you can't find outside the camp).


In the house/watchtower in the middle of the swamp:



-1 trap
-1 gun
-2 packs of ammo (Inside house, inside watchtower)

In the east watchtower of the lake there is:



-1 pack of ammo
-1 trap

In the most eastern watchtower:



-1 pack of ammo
-2 flares

In the cave and camp:

-1 medkit (For each place)



The bodies in 1 playthrough for me are in the general areas in the pictures and also have a chance for a medkit, they won't always spawn there, they just did in this playthrough I did with my friends.
(They should be shown through the previous images as a skull for where I found them)

The only easter eggs we found are:


Thor's hammer in the cave



A image of a deerman (Just cause it looks cool)



A random house in the distance below the map (Could have no revelance or something, I don't know but you can find out)



If me and my friends find anything else I'll post it to this guide, or make a singleplayer version of the loot for people doing it alone if it's that different.