The installation process of ZSNES is actually quite simple. Almost no work is required and it can all be done graphically through Synaptic if one wishes to do so but here we will simple use the terminal to save time. First off, let us update synaptic.
sudo apt-get update
Now it is time to install ZSNES which is found in the Ubuntu Repositories, if you do not have Ubuntu or would like to build from source, you can get the source code here.
sudo apt-get install zsnes
Now look in your menu and you should see under games, ZSNES. That is all there is to it! Now you have the emulator installed, it is basically just like the console. I have found that I have experienced some glitches with sound though and I would recommend going into ZSNES then Config >> Sound then setting the sampling rate to 8000HZ only if you experience sound lag. Also, you may have to install these files and I have read that you could try this command:
sudo aptitude install libsdl1.2debian-alsa
Do not forget to install your USB-based gamepad to get the most out of your gaming!