Online play question

Me and my friends want to play some classic co-op games over the net and I thought arcade emulation would be best for this due to more players. But Ive never installed MAME before and have no idea how to play an emulator online..I know this question might require a long detailed answer but thought there may be some really helpful people out there

Mame is one of the more confusing emulators to set up, I still have trouble with it, I have never successfully set it up by myself, I always needed to find it pre set up.