The PHENIX experiment at the relativistic heavy ion collider (RHIC) has measured transverse energy and charged particle multiplicity at mid rapidity in Au+Au collisions at center-of-mass energies √s_NN=19.6, 130,and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments and experiments at lower energies. The √s_NN dependence of dET/dηanddNch/dηper pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dE_τ/d_η and dN_ch/d_η is similar at all measured incident energies. At RHIC energies, the ratio of transverse energy per charged particle was found to be independent of centrality and growing slowly with √s_NN. A survey of comparisons between the data and available theoretical models is also presented