In addition to the above, try to walk down as many of the main systems as possible (especially feedwater, condensate, cooling water systems, accessible portions of safety systems, main steam, and the turbine). For the systems like feedwater and condensate, try to walk them down from the start to the end, to help get a feel for where the system is, and what the flowpath is. This will help immensely once you get into the systems class and the simulator. Going on rounds (where you typically examine all the systems in a given area) doesn't always help you understand how the system actually functions.