Arcade instructions?

I just recently went into the arcade to check it out. How do I find out how it works without guessing 5000 key combos.

 

It depend on wich game you like to play !!!

EX: street fighther do a search with google for this game you will
find tons off sites with instruction and combo print instruction
and go back to arcade and you will be king off the world

I have run a arcade for 4 years if you need a specific instructions
for a specific game just tell me......