Zone 3/4 Tube station on the Central Line.
The station entrance and the walkway to the platforms is decorated with mosiacs from Alfred Hitchcock's life and films, as he was born in this area.
Access to both platforms is up a flight of stairs. This is where the two eastern branches of the Central line meet, so if going east do check you are on the correct train!
To reach Leytonstone High Road from the station, take the left hand underpass. The right hand side leads to a mainly residential area, although confusingly there are bus stations on either side.
It's worth noting that Leytonstone High Road Station on the Overground Gospel Oak to Barking Line is only a short walk away, and that interchange between these two stations is a valid "out of station" interchange on Oyster PrePay (i.e. you'll only get charged for one continuous journey, rather than two separate ones). (Source: uk.transport.london)