Ganesha is a well known deity. He is easily recognisable due to his elephant head. There are several stories about how Ganesha came to have the head of an elephant, but symbolically it represents wisdom. However, Ganesha is best known as the remover of obstacles and as the one who brings new beginnings.
If you would like to know how you are doing in your yoga practice, take a look at your life. If you do not bring your practice into your daily life for self development, then yoga will be of no great value.