The biggest obstacle in training someone to run a marathon is getting them to the start line healthy. There are several options for you: There are many good books and I personally recommend any of Hal Higdon’s books. He can guide anyone, from the beginner to advanced and many people have run under 3 hours using his training methods. I would also encourage you to take one of the USATF on-site coaching courses which is typically a 2 days commitment (www.usatf.org). I would not recommend the coaching course you can do online because the seminars are far superior and a provide more in-depth training. Good luck!