This video is an adequate (albeit very brief) tutorial on how to do the basic, classic coin matrix
effect. You've got 4 cards covering 4 coins, and the coins travel until they're all under one of
the cards.
There are just two sleights you need to learn in order to perform this. Neither
is especially difficult, although you might want to start with larger coins to make the moves
easier. And be aware that a good mat is essential for this. The handling just isn't possible on a
table-top, not to mention the fact that on a table-top, the coins would be making some noise when
they're not supposed to be.
For a beginner, this is a good intro to a classic routine that
has spawned countless variations.