I am not sure what the virgin super hub is.. but assuming it is a router with ethernet ports.. and you have one spare ethernet.. then yes, a TC is a great device for you..
I am not sure if you are asking for buying info or setup info because you have bought one.. but the setup is simple if you load the 5.6 airport utility.. I cannot tell you how to do it from the internal version 6 in Lion.
Download and install.. this is simply a more tool version of the utility.. whereas the Lion one is more a toy version.
Go to the manual setup, then internet tab.. down the bottom you will see connection sharing.. the option to choose is off, bridge mode.. update the TC..
Then you can plug it into the virgin router and it will simply work in the network as a network drive.
Wireless can be tricky but for now leave on auto.
If you actually have issues.. think of the network as the washing machine.. get the technician in to fix it.. just like you do the washing machine.. I find it hard to understand why people expect to be able to do everything themselves.