I learned how the pieces move... now what?

Like the title said, I know how all the pieces work. I know about forks, pins, discovery etc. The only opening I know is e4, and thats about it ... I know that you should control the center, and develop, but not exactly why.

So what exactly do i start learning, and how?

Now you have to choose a starter pokemon.

The first thing you should learn is how to take losing a frequently as the gift of education.  There's a lot of "Boy, I'd better not do THAT again" involved.

Play, play, play.

That's all the "how" and "what" you need to know for now. After 100 games, consider coming back asking for tactic training and stuff like this.

Watch these 5 videos. Make sure you really understand everything he is saying

http://www.chess.com/video/player/everything-you-need-to-know-start-playing-chess

http://www.chess.com/video/player/everything-you-need-to-know-the-opening

http://www.chess.com/video/player/everything-you-need-to-know-tactics--strategy

http://www.chess.com/video/player/everything-you-need-to-know-the-endgame

http://www.chess.com/video/player/everything-you-need-to-know-bringing-it-together

Once you control the center you can try to push your pawns through. You usually concentrate this on one side of the board.

The control of the center prevents the opponent from quickly shifting his pieces over to the side they are needed.

Try to bust the opponents kings defenses or try to force the opponent to exchange pieces for pawns by threatening to promote them.

If you are ahead in material try to exchange so you relative advantage becomes bigger.

These are the basic strategic ideas after the opening phase.

Tactics training, tactics training and more tactics training.

Now real one of Jeremy Silman's books about imbalances.  It helps you to understand what's going on in the position.  Yes, you need to practice tactical vision, but at some point you need to develop and understand on what's going on positionally.

Get a book of games where every move is explained. That should keep you confused for a while.

I have 3 of his books and I like them a lot, but I think that is a little too much for an 800, maybe 1300 at the least

Now, get your opponent into a position (while having a good one yourself!) and use the tactics you've learned if possible-pins, forks, skewers, and the most powerful one, discoveries. Also, go over tons of grandmaster games.

You play as white. Push e2 pawn to e4. Black replies d6. You reply e5. Black dxe5.

Now you learn you just lost a pawn and cannot take it back. And black has double pawns. Good place to start.

Lets play..I started in january

Exactly why, again, just play. You won't learn chess just by reading, and certainly not on the forums.

learn how to checkmate with a king and a rook

Now,You know how to play Chess;