Beginning Sewers sometimes seem to have a hard time with selvage and folding fabrics to cut a lay out.  The best way to know that you have your fabric laid out correctly is to make sure you have a fold on one side and the selvages meet on the other.  If you have a fold and 2 selvage edges than you need to refold BEFORE cutting your fabric.  This will ensure that you have enough fabric to complete your project.

The first photo has the fold at the bottom and both selvages at the top with the cut edges at the left and right.  This is the correct way to have the fabric laid out.

The second photo also has the fold at the bottom but has selvages at both the right and left side with the cut edges together at the top.  This is incorrect and will cause you all sorts of problems. Both photos contain the same piece of fabric, but how you fold them will change the width of the fabric and your pattern pieces will not always fit.