Hey! I have run the full marathon once, and the half twice (maybe 3 times) and a bunch of other strange distance events (5,8,10,and 13k).
Training is a commitment. You know that already. It is good to have a plan.
Do you have a local running shoe store (not a major chain, like a mom and pop)?
These places will put you on a treadmill and analyze your gait and pair you up with the right shoes.
You might pay a few pennies more, but the analysis is worth it. Your shoes are the most important part of the adventure.
Plus you would be supporting a local business, which is always kinda cool.
Don't waste your money on other fancy stuff yet like GPS and fancy bibs and shirts and shorts and socks and water belts. Wait to see what you feel like you need once you get going.
There is a good online resource, www.halhigdon.com
I used his plans for all of my races. I trained at the intermediate level. You can expect to run short/intermediate distances 3 days during the week, and one long run on the weekend. I highly recommend his schedules. The longest training run I did for the full was 20 miles. That meant on race day I had to muscle out the last 6.2, and it was fine. They gave me beer at the finish line.
Don't train to win the thing, unless you are Kenyan. Do it for the other benefits. You will feel so good and in shape.
There were mornings I was running 9 miles at 4:30 in the morning before work. Crazy!
I HIGHLY recommend running the full marathon ONCE!!
I never want to do it again, but it is one of the things I've done that I am most proud of.
Feel free to PM me if you want any more of my ideas.
Good Luck!!