you will need a deck of cards, you can find some here [url removed, login to view]
next step you deal cards to the screen with a deal button, discard option as well
you need to have an interface to deal cards to the screen, and you must deal the cards when the user uses the interface.
If you choose to deal cards from a standard deck of cards - you will need to ensure the same card is not dealt twice
drag/drop part - the player should be able to discard (get rid of cards). They will do this BY DRAGGING THE CARDS to either the deck, or dealer, or some other location on the screen that visually indicates it is the discard pile (no mystery discards) when the player drags a card to discard it. When a card is discarded you may choose to deal a new card or not.
You can work on this in jsfiddle, the final will need to work in a wordpress page.