Well, that depends on how much makeup you want to wear. The basics, for green eyes, best eyeshadow colours are pink and browny-pinks, eyeliner in dark purple and mascara either black or dark green. Almay (which you can buy in any drug store) actually has coordinated makeup sets based on colouring and they work pretty well.

Blush is a bit trickier, but a rule of thumb is that it shouldn't be any darker than your "natural" blush and if you blush a lot naturally, I'd say even lighter. Lipsticks you're probably best staying with neutrals and again, brown undertoned pinks.

For everything, if you're not used to wearing makeup? Go light, even if it's formal. Err on the side of caution. Also, most places like Shopper's or even the Bay or Sears will have free consultations, or at least women working there who will be able to help you pick out what's best.