Multi wavelength studies of protoplanetary discs The early evolutionary stages of a pre main sequence star are characterised by the formation of a dense accretion disc. These discs provide the environment and material in and from which planets are expected to form. At this epoch circumstellar material is accreting onto the central star while small dust grains in the disc interior coagulate into larger objects and gravitationally settle into the mid plane. These are the first steps of planet formation. The study of the dust properties (e.g. grain size distribution dissipation timescale) in protoplanetary discs is then fundamental to understand how planets form. In this thesis I present three works aimed at studying the formation dissipation and long term evolution of protoplanetary discs respectively. The first project investigates the properties of the young binary system Haro~6 10. I present the results of multi wavelength high spatial resolution observations of Haro 6 10 aimed at characterising the large and small scale structures of the binary system ...