Really depends on what you are wanting in a bar. Are you just wanting a surface to serve drinks on with bars stools and a kegerator/keezer or do you want a bar with a sink, extra outlets for a blender, and custom lighting.
If you just want a surface to serve drinks on, there are some great sites for premade bars that you can find with a quick 'google'. Im afraid if you are looking for the other options but don't have much skills as a craftsman it could be a long and perhaps difficult road.