I need some help with arcade games emulation!

I was trying to run some arcade roms (AKA. KOF, Metal slug, etc.), but I do not understand how the emulator works (I was trying to use MAME).
I had some problems with the controler configuration, and i never understand how to run a game.If someone can gove me a hand or two... would be very apreciated.ThanksNote: The MAME emu was very diffucult to me. If someone knows an easier emu with a good rom compatibility... it would be very apreciated.