For a beginner, the best bang-for-your-buck is either theFocusrite 2i2or one of NI’sKomplete Audiointerfaces. If you need more channels (for recording drums or a large choir), you will need a larger interface. I’d check out theFocusrite 18i8. Eventually, you might also want to upgrad...
Currently, I use the Focusrite Scarlett 2i2. It's nice, for some home recording as well. Software OS I'm always using the latest version of Apple's OS. When there is a new, I wait a few weeks, and then try it as well. This way most of the first bugs get always fixed first. ...