Having gotten back into cycling in April of this year I have been enjoying my time on the bike and getting comfortable again in the saddle. Now I think it's time to add some structure to my riding to help improve fitness and get me off of the 17-18mph plateau. I'm looking to improve speed, endurance, and generally have more fun, not race. My end of summer goal is modest (ride 2000mi - I'm at 866mi now). But my real goal is to be able to participate in the STP next summer (205mi Seattle to Portland).
So, does anyone have some book or magazine recommendations on where I can learn more about structuring a good training program? I am looking for advice on proper nutrition, intervals, power training, and endurance training.