Back when I was in Seattle and had a board game group. We often started our sessions with 'light' games as a warm up waiting for everyone to arrive. Then we talk about what we want to play (and if it was a 'we know the rules' or 'we're going to have to figure this out' game).
In short, I think it's important to talk about expectations and what type of board game is the group is interested in playing? For example, my wife does not like board games that take 4-5 hours so she usually sits those ones out.