Notme, I think the most important lesson that I learned is to be very careful and conservative when starting up. Last year when I broke my tibia it was because I tried to do too much too soon, and that's a danger because the general rule of thumb for running is that the cardio system improves most rapidly, then the bones, then the tendons and ligaments. The lag time between bones and tendons improving behind the quick way the muscles, heart and lungs improve is what can make a for a dangerous period.
That dangerous period last year was further exacerbated by the fact that for whatever reason I found that I love running. Something about it that sometimes when I'm running I don't feel like stopping. Then I found out a broken leg will stop you. Stopped me for 4 months.
From what I know now and what I've read about, a really good program for people who are interested in including running in their lives is the Couch to 5K program an example of which can be seen at
Cool Running :: The Couch-to-5K Running Plan . It gives a safe approach for a person to build up to running 3 miles or 30 minutes after 8 weeks. My general feeling is that most people should just go with the time-based schedule. We often think of running as something that's supposed to be fast, but hard fast running is very dangerous when the bones, tendons, and ligaments aren't built up to that yet.
Which then leads to probably the most important thing that many people seem to have to learn early on -- Slow down! Seriously. When adopting running, you should aim to run most of your miles such that you could have a conversation with someone beside you. This conversational pace is quite useful to building aerobic fitness and preparing the legs in a gentle enough way to help avoid injury.
This year, for the first 10 weeks I was running, that's mostly all I did. I was slow. But that was fine. Then I just carefully began adding some more time and distance to the runs with most of those being run at a pace where I could have spoken in full sentences.
It's hard sometimes. We all kind of grow up with the idea that running is something fast, something hard. But one of the most important steps to take to get running is a step back in the mind where running isn't about how fast you get there but about learning how to run at a comfortable easy pace that feels like it could go for nearly forever.