The total and partial photoionization cross sections, branching ratios, and photoelectron angular-distribution asymmetry parameters have been calculated for atomic radium (Z=88) for all subshells from the 7s valence shell down to the deep n=3 subshells. The relativistic random-phase approximation, the relativistic random-phase approximation modified to include relaxation effects, and the relativistic random-phase approximation modified to include relaxation effects and Auger decay were all used to determine the relative importance of various many-body effects such as interchannel coupling, core relaxation, and Auger decay. Comparisons are made between the various theoretical models and experimental data for the total cross sections. Interchannel coupling was found to be important for most subshells. Relaxation effects were found to be significant for calculations of the total cross section above the 5d threshold and to have a very large effect on the 5p partial photoionization cross section.