Throughout the ages artists have been seen and examined by their self portraits, often giving a glimpse of their brilliance and as a small window into their lives.
It is no different when taking photographs and to become your own subject involves considering how you are perceived by others.
Our camera is a friend that helps us to capture the world around us, it accompanies us everywhere and we use it to create the truths and tricks of what we see. When we point the lens at ourselves it all becomes more personal as we reveal ourselves to others.
A self portrait is only ever posed, other than moving picture or pure chance the camera is set up and you must position yourself. This may not have to end up looking formal so try to think about how you want to look.
Maybe practice in front of the mirror and try different faces to get to know what looks best. Obviously with a modern digital camera no practice is required because you can just snap away to your hearts content.
Later you can discard the bad and keep the ones that suit. Close ups are often more revealing and easier to manage that full shots but like in all photography practice is everything.
You will soon get to know how to get the best out of your camera. You will need to try and find a way of relaxing if you are quite self conscious, maybe by thinking of a certain thing or focussing on a certain object. It is all trial and error.