I think this sounds like a fantastic goal!!! It is going to be HARD, but it should also be FUN!!

My guess is that nutrition is going to one of your bigger challenges, so the book you mentioned might be a good idea, although I haven't read it. However, keep in mind that every body is different and therefore, nutrition needs differ very much from person to person. Also, as you train more and more, you will probably find your own nutrition needs changing a lot. So, you will have to read your body very carefully to determine what it needs.

Carry more food with you than you think you will need, and eat BEFORE you get hungry. Also try different sports drinks. You will probably need a good amount of electrolytes, but everyone has a different tolerance for sports drinks, so find one that doesn't upset your stomach. Another thing you could try are cliff shot blocks. I always bring them on all my rides and can do fine with plain water and shot blocks for electrolytes.

Over time, you will build a pretty strong and efficient aerobic engine. That efficiency will manifest in your ability to utilize fuel (carbs) well. However, before you get to that point (and even after) you need to be hyper-aware of how you are feeling so you don't bonk. It is NOT FUN to run out of gas miles from home!

Good luck with your training and keep us posted! I am going to live vicariously through you because I am bailing on my friends' double century next week due to having been more focused on intensity this season and so haven't had time to train for that distance :-(