London Tube - Easy to use?

[Rave]

Just get the ordinary train from Gatwick station- the Gatwick Express is a ripoff unless you really value a 10 minute time saving.

Fare prices are all available from here: http://www.tfl.gov.uk/tickets/default.aspx. If you're travelling after 9.30am then you only need buy an off-peak ticket, which is much cheaper.

[MartinEve]

If I can add 2 pennies (we don't do cents over here!), the only thing to watch out for is on lines such as the Northern Line where there are different branches; High Barnet branch, Charing Cross branch - just watch out for info on the overhead boards and make sure the train goes where you think it does.