Teaching Arkham Horror to new players
If you are acting as a guardian, you can simplify a bit the part about the monsters movement  as you will do it and focus more on the parts of the turn their players can actually do an action.

Giving them a quick reference card before you explain the things can help them follow better your explanation. 

Also with many new people I'd maybe do a pre prepared sample turn with just 2 or 3 characters and monsters to show them the mechanics of the game.