IfI buy a second hard drive, which is better, internal or external? Is an external plug and play or does this lower than a newbie need someone to set it up?

farang, like everything else it depends on a number of things such as what you currently have available for slots and ports as well as what you will be using it for. All hard drives nowadays are plug and play so that shouldn't be a concern. If you have the bay space available in your computer, your hard drive will likely operate faster connected internally. Of course a lot depends on the connection port (ie firewire can be faster). If you intend to use the drive for video editing and direct applications vs storage an internal may be the better choice. If you just want storage then it really won't matter which one you get unless you don't have enough ports to support the drive available. In the long run for most applications you will be ok either way you go.