Too Much, Too Soon

I do not believe it, my fourth run and I feel like I have done too much too soon as I am having pains in my knee. Been looking online and also asked my running coach and both say it is a common thing for new runners as you simply have not used those parts of your body like that before. So it is just a case of a day or two of rest and then back into it. I found out that using my Nike+ GPS application that I have on the iPhone can also be used for indoor training so even though my route will not be mapped out, my work out still will. I think my biggest problem, being so new to running might be a lack of warming up properly and stretching the right muscle groups, or for that matter knowing the right groups to warm up. I asked other Nike+ users what was best for them, and the general consensus was that a few jumping jacks or high kneed running the spot was a good start to warming up before starting to stretch as stretching alone before warming up can cause muscle damage. Now I know my problem. I noticed that many users who had sustained and injury all got back into it after rest by the way of some simple exercises and also the use of an elliptical trainer, as this was a way to slowly warm up the body and all the muscle groups, luckily for me I own one, so looks like gone are the days of it being used as clothes dryer.