I signed up for the San Francisco marathon, which has forced me to run consistently if I want any hope of being able to run the whole thing. I run after work 2

I signed up for the San Francisco marathon, which has forced me to run consistently if I want any hope of being able to run the whole thing. I run after work 2 or 3 times a week, and go for a longer run each weekend. The marathon is in 3 weeks, and after that I'd like to better round out my fitness (right now it's just a bunch of running with a few pushups and crunches here and there). Ideally I would do some weight training in the gym at work, and start taking swim lessons for the fitness, drowning-avoidance, and even social benefits.