Any teachers out there have any tips on teaching ESL?

I am teaching ESL to 3 Korean adults, all with varying abilities, but all who can speak and write fluent english. I am also tutoring their spouses and children, some of whom are fluent, and some of whom are beginners. I am in teacher education, so I know where to start, but if anyone has any suggestions I would REALLY appreciate them!! Also, does anyone know of or have any handouts, tests, diagnostic material, games, vocabulary lists they can send me? Thanks a lot, let me know!