Internet connections should work instantly after installation as VirtualBox automatically configures it for net access. When it comes to USB devices, VirtualBox automatically detects new ones and asks you if you wish to use them. There is no drag-and-drop function from your native desktop into VirtualBox but considering it's free, you really can't complain. However, you have to install a 'Guest' add-on first (which only takes a few seconds) and it's not made very clear how you actually access the shared folders once you've set them up. VirtualBox allows you to define 'shared folders', which can then be accessed from within the operating system you're running in VirtualBox.
Integration with your native environment is straightforward although not as slick as Parallels.
