Hi all,
I have been a runner since I was a kid (now in my mid 40s). I would highly recommend the monthly "Staying the course" articles by Runner and Physical Therapist Joe Uhan on irunfar.com covering efficient running form and injury prevention, management and treatment.
Some general pointers:
1) Aim for around 180 foot strikes per minute (count how many times your right foot hits the ground for a period of 10 seconds – 15 is what you're aiming for) if you're much below this you're probably over striding.
2) As a beginner it can be hard work to maintain good stride rate and form for any period of time, don't be afraid to stop running for short periods to allow yourself to recover. Learning to run well is hard when you're not tired, almost impossible when you are. "Flog yourself" a maximum of once a week.
3) Expect a bit of musculo-skeletal pain, but not too much. I know that's not very specific, but pain is entirely subjective. Objectively if pain is causing you to limp then it's definitely time to bail on the run.
4) Don't be afraid to see a good (seek recommendations from other runners) Physical Therapist whether or not you're injured, they will observe your posture doing 1-legged squats, lunges, bridges etc. checking for muscular weakness, poor coordination or mobility in running specific movements, and can give you advice and exercises to correct these. You can DIY this to some extent with the book "Anatomy for runners" by Jay Dicharry (not as dry ,or as long as the title might suggest)
5) If you become injured think about why it happened.
6) Not running for long enough will generally cause your injury to go away, but if you haven't addressed item 5 then it's probably going to come back.
7) Beware of lists "5 sessions for your best 5k!" type of stuff, great for selling magazines, generally poorly thought out and sometimes idiotic.
8) As with most things read widely but sceptically. Beware of fads and gurus.
9) If you're running for an hour or less in a temperate climate, you don't need a drink, if you're going longer, let your thirst be your guide.
10) Trail running is good, but so is road running if you can run on soft surfaces, but roads hurt, you probably need to pay more attention to your technique.
11) Running frequently and moderately is good (3 or more times a week, building up gradually)
12) The majority of work should be done at the hips, everything else should, ideally, work smoothly and relaxedly to allow your hips to exert force backward and downward on the ground.
To carry on further would be unlucky perhaps ;)
Dave