Check the website:
http://allyours.virginmedia.com/webs...ervice.do?id=2
Cable is basically a separate service and line (from the normal BT line) that will need to be installed somewhere on/in your new property.
Couple of holes drilled through an exterior wall.
Some thin cable run on the outside of the property, and a couple of small wall fixtures (just above the skirting level) inside the room where you'll use the services.
That's if the new property hasn't already had a cable installation.
(You will also need the permission of the property owner if you're renting.)
.... and of course, the cable network doesn't have 100% coverage, so there's a small chance that it may not be available anyway.
The basic 10Mb broadband, by itself is £20 a month, or £24.50 with a phone line.
Minus whatever offers you get for the first couple of months.
Personally, I think Virgin/cable is 'expensive', although others consider them good value.
If you work out the price of BT's broadband with line rental etc. then the Virgin Cable alternative probably compares quite favourably, especially since the potential speed you're being offered is a (bad) joke!
I've stuck with them primarily because I have better things to do than spend 3 hours a day negotiating with British Telecom's customer services!
Check over any 'offers' carefully, and read all the small print.
There are a few Virgin staff (and others) who haunt these forums:
http://www.cableforum.co.uk/board/56/
for help on installation, pricing, troubleshooting etc.