I was a first-time marathoner in 2012 and I found Hal Higdon's site very useful. http://www.halhigdon.com/
FWIW, training for a marathon isn't too complicated. Start at least 18 weeks beforehand. Run about 10-11 miles during the week and do one long run on the weekend, building up to 20 miles two weeks before your race.
I did 4 marathons, 200lb guy with 5hr finish times. 3 Marine Corps and 1 Big Sur. I enjoyed each and every race, except my first. but I would take that painful race again anytime.
Tip for back-to-back marathons: Based on my experience, two back-to-back is a killer. I would NEVER enjoy NYC after running chicago, if chicago is going to be your first. Again.. this is my experience and I would never do it. But some people are driven and they are able to do it.
For Training: HalHigdon is best and simple.. The way I do every time is, take 18 wk plan, and stretch it to 36 weeks.. that way, each week is repeated twice.
As you have lot of time (you might think ;), make sure you include Weight Training and Speed Training. Helps a lot.
FWIW, training for a marathon isn't too complicated. Start at least 18 weeks beforehand. Run about 10-11 miles during the week and do one long run on the weekend, building up to 20 miles two weeks before your race.