V-Flyer

to gaurantee a reserved seat via the virgin web site how early do i have to get to check in ?[:?]

Technically Joanne, there's no such thing as a 'reserved' seat when flying.

You can increase your chances of getting the seat you would like by checking in at least 3 hrs before your departure at the airport.

The best option would be to OLCI (online check-in) 24hrs before, but again, your seats selected could change by the time you get to the airport - they probably wont, but you never know.

Regards

The aircraft operating the route can change so configurations may be different - for example, the same crew can fly an A340-600 and a A340-300, so the two are interchangeable from that perspective. Anyway, if you've selected a certain seat on the -600 and it is swapped with a -300, your seat may no longer exist.
However, this isn't common, so I wouldn't worry too much -especially if you're flying from LGW (Gatwick):D

VS.