You're already on the right track, getting a solid training plan written out. I used the Runner's World Smart Coach program for my first HM, too. It was SUCH a huge benefit for me since I really had no idea how to train.
As you start to add longer runs to your routine, start experimenting with different drinks, gels, and other mid-run foods to find what works for your gut and what doesn't. If you can find out what they'll be serving at the aid stations at your race, try to use the same products so you can see how they help/hurt your run. I really cannot emphasize this enough, because there is NOTHING worse than tummy trouble during a run.
For now, just enjoy building your base, and don't get into a training mindset until you're closer to the race. You don't want to burn out your brain by forcing it to think about training for 7 months!
"If you don't take care of your body, where will you live?"
"It's supposed to be hard. If it wasn't hard everybody would do it. It's the hard that makes it great."