In order to practise meditation we must satisfy the requirement of stillness of the body, an erect spine and closed eyes. These are important disciplines that allow energy and senses to become focussed upon our meditation. There are simple modifications if you are not able to assume the classical cross legged positions.
Dhyana or Meditation itself has four stages. These are relaxation of the mind, concentration of thought, elevation of the soul, and expansion of the spirit. These ideally culminate in varying degrees of peaceful or heightened experiences of consciousness.