There are tons of free machine knitting patterns on the internet. Most patterns can be made on any type of knitting machine. If you don’t have a manual for your machine check out this free manual source http://knit4profit.com/2012/07/11/free-resources/ .
What is a shrug? It is basically a short version of a sweater. Measure the length of your arm, the width of your back, and repeat the arm length again. A good pattern source is the free version of Knitware. What I have learned using this program is that you can create a pattern in sections by taking portions of the pattern instructions apart then put the parts you want together to create a totally different pattern. You can create different types of sweaters once you have learned the basics of machine knitting and the basic shapes of a sweater. What I have found to be the most difficult part is learning the correct body measurement and determining the correct ease allowance to apply for the type of garment to be made. An excellent book to add to your library is a hand knitting book by http://knit4profit.com/2012/03/15/knitting-book-reviews/
You will learn about body shapes, etc. First you decide the widest part of your body, i.e. hips, bust, waist. If your waist is the largest then you will use that measurement times stitch gauge to get the number of stitches to cast on and then gradually decrease as you knit up on a bottom up sweater pattern. If your garment requires more needles than your machine allows, the next step is to divide your pattern in half or if knitting with a ribber attached use the “U” shape technique which extends the needle bed to 400 needles.
I learned by drawing a basic diagram on paper, plotting measurements, knitting a swatch, and buying cheap yarn to knit a test garment.