Recently, there has been increasing interest in the development of covalent surface supported polymeric networks. This is attributed to the fact that they are thermally, mechanically and chemically more stable than those based on hydrogen bonded or metalorganic frameworks. The formation and characterization of organic nano-networks on metal surfaces is important for applications such as gas sensors, catalysis and molecular templates. In this thesis, strategies for the formation of covalent networks of 5,10,15,20- tetrakis(4 aminophenyl)-porphyrin (TAPP) and 1,3,5 tris(4aminophenyl)benzene (TAPB), both of which have amine groups that are attached to phenyl rings, were extensively investigated on Au(111), Ag(111) and Cu(111) surfaces. The strategies employed to form covalently bonded networks are based on reactions between the amine groups on the TAPP or TAPB molecules. An investigation of the self-assembly of these molecules, deposited at room temperature, on different metal surfaces was carried out to investigate the effect of intermolecular and molecule-surface interactions. The surface elevated at different temperature was employed to investigate the formation of networks through the polymerization of these molecules at various substrate temperatures. Polymerisation of the TAPP molecules is expected to form networks with a four-fold symmetry networks whereas the reaction among TAPB molecules would gave three-fold symmetry networks. Further investigations were carried out on a polyimidisation reaction between the amine molecules and the anhydride groups present on 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). All samples were studied in detail using scanning tunneling microcopy (STM) and X-ray photoelectron spectroscopy (XPS) measurements to investigate the structural and chemical properties of the networks. In addition, ultraviolet photoelectron spectroscopy (UPS) and synchrotron based techniques were utilized in some of these studies. The ordering observed in the resulting structure is largely determined by the initial molecular coverage, substrate temperature, type of single crystal used and the deposition rate.