Jeff,
That is great that you are thinking and planning ahead. I can't really offer any advice with regards to OCS, since I went through the NROTC program, but basically as with all programs, it is a cram course used to indoctrinate you in to the ways of the Navy. I would imagine that your time will be at a premium during OCS and it might be better to memorize items now in your free time, I don't know exactly what is in your packet (possibly rank structure, chain of command, general orders, UCMJ, core values, and the list goes on...??)
Depending how familiar you are with the Navy, and with the information in the packet that was given to you will probably help decide how much time you spend on it. Maybe Matt or one of the other OCS guys can shed some light here for you, I am just making an educated guess based on my experiences in the Navy and when I went through the Naval Science Institute in Rhode Island, (the knife and fork school, equivalent to OCS that us Enlisted Commissioning Program people have to go to prior to NROTC).
As for studying ahead for API and Primary, that's great, but also pace yourself and take each hurdle at a time. More than likely you are going to have time between OCS and API, and then again between API and Primary, the infamous "pools". After OCS and when you check into API, get your books and start working ahead on the ELOs (questions at the end of each chapter) and that should more than get you ahead of the power curve, and make things easier for you during API. As for Primary, it is a good idea to get your hands on some Emergency Procedure Flash Cards (which can be found at Wings, an Aviation Specialty store in Pensacola) and start getting those down. Also, if you have a Marine buddy, get your hands on a Red Rocket guide, which has all sorts of useful information in it.
No, it sounds like you are on the right track Jeff, and more prepared than most people I have talked to, though it sounds like a bunch of you on this Forum are going to be there at the same time, so that should be interesting. Anyways, all the best and good luck,