how do I know which buttons on my keyboard perform whatever functions?

[spiketyrrell]

How can I play emulator games with someone in this house that is on a different computer? Also do you know how to tell what buttons perform certain actions on the gens or fce (nes) ultra emulators? I am new and scared.

[hagbard]

To know the default keys of the emulators and to remap them, the best option is, as usual, to take a look at the documentation (readme.txt, a help file, etc).
For example Gens: "Options" -> "Joypad" -> "Redefine Keys".
FCE Ultra: "Config" -> "Input" -> "Port 1:" select "Gamepad" -> "Configure"

To play with someone on a different PC, the emulator needs to have implemented the Netplay/LAN/ etc feature. Again, read the docs, it differs a lot from one emu to other.

Hope it helps :p