There are two ways to do machine embroidery - to use either a digitized pattern (which you can either do yourself using a digitizing program, or get commercially done) or freestyle.
Freestyle allows you to use your machine skills & imagination so much more.
To freestyle machine stitch, transfer your pattern to the fabric in the same way you would for hand embroidery, and then, like you would with hand embroidery, plan your colours and stitches.
If you have a specialised embroidery machine, there are a number of stitches you can use, but you may want to start with deciding on stitch length for your stitching.
You can also get specialised metallic threads that you can use through your embroidery machine, as well as normal threads.
I hope that this helps - perhaps Fritsau (our Machine Embroidery Guru) can give you more information - especially on digitising?