Cover the furniture and floor with drop cloths. Apply masking tape to the bottom and top of your walls and outlets. This allows you to get your wall the desired color and help it have a uniform color. Then select the color you would like. Talk with the associate in your local hardware store to determine the difference as well, as to determine which one is right for you.
Different finishes are ideal for different rooms.
Apply paint from the top down. Or use a zigzag formation. Many prefer to have the zigzag format to prevent streaking on the walls after they dry. Whatever you do be consistent. Wait a couple of hours and allow the paint to dry thoroughly.