Back when I was running steadily, I learned a lot from the discussion boards over at Cool Running
. The "Basic Training" section has a lot of information about the mechanics of running--stride length, heel vs. forefoot striking, how to breathe, etc. I also liked The Complete Book of Running for Women
, which covers a number of other useful topics.
Hope that's helpful--sorry I can't be of more direct help! I never was able to find a running gait that didn't eventually damage my knees.