Luca,

I mainly work with .NET 2, so for LINQ advice you should count on the
guru's here.

However, concerning the approach your taking: start the same as if you
were architecting a database you'd start with a schema. Similarly for
your code, start with creating interfaces to show relationships
between your objects. For example:

/*****************************************/
interface ICard {
// jack, 2, 3, ace, etc
string name;

// clubs, spades, diamonds, hearts
MyCardColorEnum color;

// object reference to the deck
IDeck deck;
}

interface IDeck {
// cards in the deck, ordered
IDictionary<int, ICard> listOfCards;

// gets a random card
ICard getRandomCard();

// gets card from a specific location
ICard getCard(int location);

// gets the top card of the deck
ICard getCard();
}
/*****************************************/

Good luck with your study!

Regards,
Jeroen

Providing you are using .NET 2.0 or later, I would use a generic list
of a class object of a class that defines each card.