Re: textual onramps for players: I would argue that the play style of Forbidden Lands advocates exposing players to the fictional culture only through play at the table. No homework. That is part of the game function of the Blood Mist, to make it so that every adventurer is in some ways a cultural outsider to begin with. From the Gamemaster’s Guide, p. 6:

The Forbidden Lands may be unfamiliar ground to the adventurers, who have lived isolated in villages and other settlements, but it is a land with a long and rich history.
…
To convey the history and myths of the Forbidden Lands to the players in-game, you use legends. Every monster, every artifact, every adventure site and every character of importance … have their own legend. … In this way, the players build their own knowledge of the Forbidden Lands and its denizens.

Given this design, the referee tools for translating history and fictional place to players will bear a lot of the load. From what I’ve read so far, there are some solid efforts to provide useful tools (such as treating “legends” as a first order game object rather than an informal fictional element, as mentioned in the quote), but I have yet to get it to the table. I would be curious to hear about your experiences with this aspect of Forbidden Lands.