As things currently stand F/O pay starts at 3300 ish take home per month. I am a year 3 year Capt and take home roughly 5500 but this can vary +/- 300 quid depending on hours flown.
Much of this is covered upthread - yes, it's worth reading the whole thread if you're interested in Virgin. Take home pay depends on your own personal tax circumstances and pension provision. There are Virgin Atlantic captains taking home well over £10,000 a month - but they don't live in UK. If you prefer not to contribute to the pension scheme, or have alternative arrangements, your take-home pay will increase by around 10% over the figures given by 4Engines above.