I am a novice and started running 6K. I am planning to step up to 12K. My concern is that I only have concrete surfaces to run on and my frequency is 5 times a week. Will that tax my joints? What would you suggest. How can I minimize injury?
It is hard to say for sure how much you will tax your joints, as every person is different when they run - based on your weight, whether you heel-strike etc.
However, if you want to mitigate any effects that running will have on your joints, then you should look into getting more cushioned running shoes - this will help 'soften' each blow, at the expense of 'feeling the road'. It can take quite some trial and error to get the best shoes for yourself, but you will know when you find the right ones. Many of the major brands have "quizzes" or questionnaires than can direct you to the correct shoe that they manufacture (eg Mizuno, Brooks), whilst there are a number of comparison tools on websites such as RunningWorld and the like.
In the mean time, make sure that if you feel any discomfort in your joints or muscles, aside from delayed onset muscle soreness (DOMS), that you rest. If you have have muscle soreness, you can help to treat that using RICE (rest, ice, compression, elevation), however, it is often beneficial to alternate warming and icing (eg a bag of frozen peas and a warm wheatie bag) to help stimulate blood flow.
Ensure also, that you do not go straight into the run with cold muscles - that is, to say, it is beneficial to warm up with 10 minutes of jogging, fast walking, or running at a reduced pace. The same principle should also be followed towards the end of the run, slow your pace for the last 10 minutes or so (as you do not want your muscles to cool and contract when you stop abruptly). On the same wavelength, getting into the habit of undertaking some static stretching after every run will help to keep you away from injury, and make sure the blood flows evenly throughout your muscles (preventing 'knots' from forming) - for example, target your quads, hamstrings, upper & lower calves in a variety of different stretches (my personal stretch routine takes about 10 minutes after every run).
A crucial way to avoid injury is to make sure that you don't increase mileage too greatly week on week, or increase your pace dramatically - your body will get used to running several times a week, with a certain mileage, which will then allow you to increase mileage or speed up (never do both on a single run!). You should aim to increase your weekly mileage by no more than 10% on the previous week.
I suppose another way that would be beneficial to you, is to try to get off of the concrete - running on local pitches, fields, common areas, woods etc. Not only will this help to reduce the impactive stress on your feet (the surfaces are much more cushioned than the concrete), you will help to build up strength in muscles that aren't used quite so much when road-running (muscles that help support during the uneven terrain).
I hope this helps, and keep up the good work - you'll reach your targets in no time :)
You should get shock absorbing shoes for sure. Do not do eccentric type of exercises before/after running you will hurt your muscle fibers and the last apply ice on your joints after every running session. You may also try to have some BCAA before/after running. First ask your doctor and then you may try Glucosamine - Chondroitine complex that stimulates the synovial fluid secretion and it is good for your joint health. Keep up the good work :-)