If you are new to running, just curious or have some questions you are seeking answers to then do visit some of these web sites.
http://www.runnersmedicalresource.com developed by some of the top Marathon and Triathalon organisers in the UK.
http://www.sportsinjuryclinic.net/ may be of use in deciding if you need further help.
If you have or are experiencing hip or knee problems you may find chi running of interest. The techique was first proposed by Danny Dreyer. Tony Gill is trying out chi running because of knee and hip pains during 2009 and so far these problems have not returned. The following videos introduce the basics:
Lots of excellent advice on all aspects of running at :