training book for newbie

Hi, looking forward to pushing my body on a new quest, just finished the Disney Marathon ( first time running one) and my wife's family is from Key West where they have an annual Swim Around Key West event, 12.5 miles. For the marathon I trained with Team in Training, the fundrasing arm of the Lukemia and Lymphoma society which provided a training schedule, fluid idea's and other topics to make the distant, while not enjoyable in the least, at least doable. I am looking for something in this vein, somthing that says ok your 16 weeks out in this week swim 1 mile on Mon, sprints on Tues etc... I would appreciate any sugestions or directions to look in for this guidance. Thanks in advance for the help:)