The Calgary Marathon is only 12 weeks away! It kind of snuck up on me. Even though I'm only doing the half-marathon, my training has to start this week: three weekday runs and one long weekend run, every week. For the training, I'm using the schedules listed at Best Running Tips. My estimate is that I'll start at around 25km per week, which I do already, and work up to 45km per week.
In order to avoid injuring myself, I've bought a heart monitor. It's not my heart that I'm concerned about as much as my legs… after 20 minutes or so my legs tend to get loose and comfortable and I can't really tell whether I'm pushing too hard. This led to shin-splints when I first started running (the cure was new shoes) and a pulled calf muscle after a rather idiotic 15km run just before Christmas (it took 8 weeks for full recovery, so I can't afford a repeat.)