I'm 2 years removed but physically, I'm sure things at OCS haven't changed. Things I did to get ready for OCS was to start out running 2 miles 3-4x a week. I did do alot of walking in the beginning but as I got better, I started running longer and I think I was doing 10 miles easy a couple months before OCS. I then scaled it back to just 5 miles 3x a week as I didnt want to get shin splints or overdo it for OCS.
If you want a fitness coach, then by all means do it. But you don't necessarily need to spend that money right now unless you're obese and trying to get to OCS. You just need discipline and a solid nutritional meal plan. That is where a nutritionist or fitness coach could definitely help.
As far as individualized programs, load up your iPod with songs and high BPM music you can run to so you're not bored. Don't start off timing yourself. Get your endurance up first and work on speed later. If you jump in too much too soon, you'll just get discouraged and hurt yourself. The speed will come with time. Robotsailor is right about one thing, don't focus too much on weights right now. Save that for after you out of OCS and you have time. You won't be going to the gym at any point during OCS until probably your candidate officer phase. And even then you'll be so busy you'll barely have time. There is more than enough PT at OCS. Not saying you shouldn't hit the weights a bit, but thats dependent on your body type and what you want to do personally.
Here are a few things that helped me. There is a podcast called "Motion Traxx" that you can download and it consists of running/biking/etc programs that are set to music. The BPM of the music corresponds to how fast you run. It absolutely helps.
There is also the couch potato to 5k program which is awesome and will help get your endurance up and time down.
http://www.coolrunning.com/engine/2/2_3/181.shtml
Next I also used the "100 Pushups, Situps, Squats" etc. programs. These are awesome and will help you with your pushups and situps. Don't be too worried about form right now, but get your muscles used to cranking these out. Especially during OCS when you will run the PFA and be extremely sleep deprived among other things and so your body will have to suck up every last bit of energy it has. There are links to the other programs on his site as well.
http://hundredpushups.com/
Lastly, set a goal for yourself. If you don't know what you should be shooting for in order to pass the PRT, then its worthless. I'm not sure what you need at OCS now to pass but for our IN-PRT, we had to pass with a satisfactory, which you should be able to do in your sleep. Strive for outstanding, don't just settle for the bare mins. Also there are pushup and situp workouts on this site as well, but check out what you need to pass for your age group.
http://www.navy-prt.com/malestandard/malestandard.html
There are a huge myriad of other exercises that you'll do at OCS, but if you can nail out the pushups, situps, run and other PT stuff, you'll be fine. Once you get good, start incorporating some high intensity stuff (sprints, etc) or run stadium steps to music too.
Good luck.