Prawn Crackers, rice/noodles and chicken rolls are obligatory. Now you can obviously differenciate your meal by having different types of rice or noodles, you could even have a vegetetarian spring roll if you're into that sort of thing.
Now the main course is obviously going to involve some sort of meat - preferably chicken or beef. Personally I'm a fan of a sweet and sour chicken, but I also like beef in a black bean sauce from time to time.
Now as long as you stick to the rules above you will enjoy your Chinese. Throw in some chips as well and it is not humanly possible for your meal to go badly.