We give a standard introduction to loop quantum gravity, from the ADM
variables to spin network states. We include a discussion on quantum geometry
on a fixed graph and its relation to a discrete approximation of general
relativity.Comment: Based on lectures given at the 3eme Ecole de Physique Theorique de
Jijel, Algeria, 26 Sep -- 3 Oct, 2009. 52 pages, many figures. v2 minor
corrections. To be published in the proceeding