Not too much really. Pretty much when new members wanna join and I'm absent for some reason or another, like I usually am on Thursdays, Fridays, & Saturdays, just let them know their accepted and will be added when I return..unless they're obviously just spamming or something of the like.
Another thing is something you're already doing, finding info on upcoming games (I.E. Birth by Sleep) or anything related to Kingdom Hearts and posting it in the FC. You wouldn't have to commit to this of course, because life comes first.
You can also request Co-Owner Banners, like how I usually have an Owner Banner, for the fanclub, featuring any character I can currently get art of (I already have one of Aqua I can make).