The idea of The Rapture, where Jesus snatches people up into heaven while they are driving their cars, asleep in bed, or walking with a friend, comes mainly from a misunderstanding of 1 Thess 4.16-17:
For the Lord himself, with a cry of command, with the archangel's call and with the sound of God's trumpet, will descend from heaven, and the dead in Christ will rise first. Then we who are alive, who are left, will be caught up in the clouds together with them to meet the Lord in the air; and so we will be with the Lord forever.
Here the author Paul is describing the return of Jesus to the new earth (cf. Rom 8:18-27; Rev 21:1; Is 65:17, 66:22). So the idea is not escaping to somewhere else, but actually staying here and inhabiting the remade world.
This makes sense when one understands that in 1 Thess 4, Paul is conjuring up images of a king returning to his homeland after victory in battle. The king is met by his citizens in the open country and then escorted back into the city.
There is an image of people "meeting the Lord in the air," but it is followed by the assumption that they will immediately return to the newly remade world.
The word rapture comes from the Latin translation of the Greek word for caught up in 1 Thess 4.17. The idea of such an event was popularized by John Nelson Darby in the mid 1800s and further propagated by books (and movies) like the Left Behind series.
Belief in The Rapture is amazingly popular in the US, but is not widely accepted in Christianity as a whole. So this Saturday, rest easy. Nothing is going to happen, certainly nothing that looks like The Rapture.
For a Biblical perspective on the Second Coming of Jesus, see N.T. Wright's book, Surprised By Hope