I'm not an OCS grad, but this is what a few ocs grads told me at marineocs.com.....
1. The Hills at OCS aren't that bad. It depends on the types of hills you are used to. The Jr's courses have a few short gradual hills and one very steep fairly short hill. Get used to running on hills if possible, it will help. I would reccomend running 4-5 days a week. Running 2-3 miles at your fastest pace a couple of times, and longer runs like you are doing at a slower pace. The shorter runs will help improve pft times and the long runs increase endurance. Endurance is key at OCS. Variation in routine is also important, don't run at the same pace for the same distance everyday because at OCS you wont. Mix it up and vary your running distances and pace.
2. Well, there are all kinds. Just lots of them. And yes, there are long and steep hills. You will find out on your first run after the pft, Da Nang is a son of a biatch. But its obviously not that bad or no one could do it right? Hey whatever motivates you to do it. Just remember while you are there, there have been many candidates before you and there will be many after you that have done it. Its all good stuff.
3. I graduated seniors this summer. I'd say to have plenty of hills in your running workout like the other candidates said. If you live in a flat area like myself in Central Florida, run up the slopes of parking garages. That's what I do at UCF.
4. makes sure you run with boots. The E-Course SUUUUUUUUUUUUCCCCCCCKKKKKKKSSSSSSS!!!!!!!!!!!