I think the best thing you can do is run with a group, especially if you can find one training for the same marathon. It'll keep you a lot more motivated than running by yourself, and it's a lot more fun. Plus if you're a techie, it's a good way to get outside and meet people. FWIW, the 2013 Chicago Marathon and the 2013 NYC marathon are pretty close together for a first-time marathoner. I would suggest just doing on…
Best subculture I've found for actually getting training help and discussion is in the 'Marathoners' subforum at Runners World message boards: http://forums.runnersworld.com/forums/runner-communities/mar...