Moss Stitch looks complicated, but is very straightforward and can bring real interest to a garment or scarf.   To create it, you simply alternate Knit and Purl stitches (so K1, P1).  On the next row you alternate this pattern, so if you have an even number of stitches you P1, K1 all the way along.  If you start with an odd number of stitches, you just need to K1, P1 on every row and this will give you the lovely bumpy texture.

Two things for a beginner to watch with Moss stitch:

1. Make sure you bring the yarn between your needles to bring it back and forth for the knits and purls.

2. Keep looking at your work to make sure that you aren't knitting on top of knit stitches and purling on top of purls... this will produce a ribbed piece of work.