Calorie Burn Calculator - This is the most accurate calculators I've found online (thanks Pike Creek Valley Running Club) for calorie burns. Some of the others give you wildly different results. I've compared this one to the BodyBugg, MyFitnessPal website, and a heart rate monitor. I think it's most accurate because it takes into account your weight, pace and duration, which all effect the burn. Most online calculators leave out one of those factors.
Pace Calculator - Know your overall time and distance, but not your pace?
Marathon and Half Marathon Training Schedules - Hal Higdon is a respected authority on the matter. Don't sweat it if you miss some training runs, but this will give you a great idea of how to start.
MapMyRun - Need to map out a run? There are other things you can do on this site like track your miles and link up to your smartphone app with GPS capabilities.
Speedwork - What is it? Why do it? How to do it? If you need to know what paces you should be doing speedwork at, check out the training pace calculator above and enter a recent race pace.
Hill Repeats - What is this? How do I do them?
Social Networking - There's plenty of social networking for runners. I personally like and use DailyMile, but there's a social networking component to MapMyRun and RunKeeper as well. It's all a personal preference.
Running Apps - RunKeeper, MapMyRun, Couch-to-5k,