So as a promoter of barefoot/minimalistic running, I guess my blog can't really be complete unless I have at least one post about how to run without your shoes. Without getting too in-depth (you can always search the topic for more info), here's some advice that will get you started.
1. Leg speed/turnover: Here's the key that makes everything work, and it is related to many of the following bits of advice. When running with overprotective shoes, it is easy to get lulled into taking long, slow strides; your heart rate may go down, you cover more ground with each step, and all that cushion under your heel feels so soft. The problem with this is that all the shock created by your landing has a direct pathway to travel through your joints and into your back; you might not notice it at first, but over time, this can create lots of pain and discomfort. Take away the shoes, though, and your insticts will quickly take over: without slowing down, you will take more short steps per minute, allowing a different landing that will prevent much of this shock from making it to your joints. You may see as many as 10 to 20 more steps per minute once you start running with less under foot.
2. Foot Strike: As your leg speed increases, you will want to make sure that the balls of your feet are the first part to touch down. This will most likely come naturally. Your instincts may be to stay in this position until take-off, like a sprinter, but this will place high stress on the calf muscles of untrained runners. For this reason, I would suggest only running short distances once or twice a week while getting used to this style of running, and keeping your average pace below tempo for the first few runs. By running slower, you can relax and learn to lightly touch your heel down after contact, giving your muscles a slight rest before takeoff. Soon, if you like, you can increase your speed, and eventually you may not want to touch your heels on all but the slowest jogs.
The mid-foot strike provides the cushion that even the softest shoes cannot replicate when a heel-strike is used. The arch compresses, dissipating shock, which would have to take a tight turn before traveling up your leg; when the heel hits first, the shock has a straight shot through your body. By using the arch, you can strengthen this important structure of human architecture; many people notice higher arches a few months after running barefoot, which are even more effient at abrobing impact. Even if you are running in regular shoes, this strike could save your knees, hips, and back from damage later in life.
3. Take it Easy: This, above all, can save you from yourself during the early days of your running. It is very tempting, after a good first run, to go out for another, longer run on the second day and maybe even the third. Please, do not be swayed! It is important to give your body enough time to realize it is sore and repair itself. At best, overuse this early in your program could leave your calf muscles too sore to run for a few days; at worst, you could cause fractures to the bones in your foot.
Fractures, even though this is a safer way to run? Yes. Just as you will soon find that your lower leg muscles, designed to support your weight while running, may be weak and in need of growth, you will also find that the bones in your foot are not as dense as they should be for natural running. Since bones increase their density on an as-needed basis, this problem will fix itself with stimulation, but it takes time. For the first few weeks, you will probably feel a bit of dull pain in the balls of your feet; pay attention to this and do not try to push the process. I ran twice with Vibrams in my first week, with three runs in between done in regular shoes. The next week, I began to increase my mileage, but kept the 2-out-of-5 run ratio going for the first month; I really believe this was the safest way to convert to barefooting.
Calf soreness is the other major warning for you to consider. A sore muscle is in need of time and nutrients to repair itself. Though some lingering soreness will go away after you begin a run, major soreness that gets worse when running is a sign of overuse. Take it easy, and remember that you will have the rest of your life to run once the process is complete. There was a time when I, after running minimally for a month and a half, over did it and ran five 1 k, all-out intervals; I was not able to run for 6 days afterward, limping around during that time. Had I tried to run anyway, I could have caused serious tears in my muscles; as it was, the tears were minor, and though I was sore for a while, I was able to make a full recovery marked by a personal best 2 weeks later in a short course duathlon.
I hope I didn't scare anyone off! It's not as bad as it sounds; if you're already a runner or athlete, you have the determination to become a barefooter. In the process, you will learn more about your body's capabilities than you thought existed. You'll become fitter, stronger, and feel more connected with your run than ever before, and hopefully remain injury free for years to come. As someone who no longer has sore hips, knees, arches, and toes, I stand by these 3 points as the key to my success. Have fun!