Follow your schedule as close to the letter as possible, and you should be golden come race day, 16 or so weeks after you start training. But as you know, long distance and endurance running is more than just running until you can't run anymore. There are a lot of other things you can do, tangential to physical training, to prepare your mind and body.
For example, in training, "go soft" whenever possible, in terms of running surface. Avoid running on pavement if you can. There will be less impact and wear on your knees and feet if you train on softer surfaces like even-cut grass, hard-packed dirt, or modern, bouncy track surfaces.
Hydration is also key. Obviously, drink lots of water and sports drinks, right? It's not quite that simple. The trick is to train your body to be used to marathon-day hydration levels by drinking marathon-day levels throughout the training period. So even if you're only running 10 miles (16 kilometers), you should still hydrate as if you're running 26.2 miles (42.1 kilometers). Technically, you'll be getting more fluids than you need. But if you step up your hydration on marathon day and your body isn't used to it, you might wind up with indigestion and fatigue.
And remember to pace yourself. For the first 5 to 8 miles (8.05 to 12.85 kilometers) or so of the marathon (or your long training runs), cut your speed to about 10 to 15 seconds below your consistent goal pace. An extra 10 seconds each minute for five minutes adds up to about 50 seconds, which doesn't sound like a lot. But it's just enough for you to hold onto some extra energy for mile 20, when you'd otherwise be running out of steam. Coaches call this technique "race day rules." They even suggest breaking for few seconds before slowly resuming running and regaining the pace, which conserves your energy for when it counts at the end of the race.
Finally, recovery days are a must. Truthfully, the human body is not meant to run 26.2 miles as fast as possible all at once, and it has to prepare. Your body needs a day or so every week to rest, both to recover to full capacity and to give muscles a chance to "learn" their new expectations.