Geoff Ollerton tells us to leave the M6 at j31 go left up the hill (often a police speed trap on the hill, so stick to 30) into Preston. Keep on until the roundabout (speed camera by the BP garage on the left) then go right onto Blackpool Rd. Keep going until you reach the ground on your left about 1 1/2 miles.
There is good parking at the Fire Station just before you reach the ground (£2 I think). If you notice there is a Sainsbury's supermarket opposite the football ground at the junction of Sir Tom Finney Way. Go right and then past Sainsbury's and there is The Sumners Pub which welcomes away supporters. Parking is mainly in the streets surrounding the ground.
As you near the ground don't be tempted to park up on the grass verges, you are likely to find after the game that you have been given a ticket for it! There may be Parking for cars at Moorfields Special School. The car park is manned by volunteers from the school and all proceeds go into school funds. Just follow the directions above and at the last set of traffic lights continue straight on for about 200 yards, and you will see the school on the left near Moor Park'.