I'm starting on the road portion of my training here in a couple of days, and part of the instructions suggest driving the knees forward, and concentrating on quick turnover. The last part I get, the first I'm a little vague on. Figured this was as good a place as any to have it explained, as I'm sure I'm not the only new follower to a Train With Eric running plan.
Dustin - Glad you asked about this, as others have had similar questions. Driving the knee forward acts in concert with quick cadence. Many runners will focus on "pushing off" backwards with their foot/leg. This can slow your cadence and you then have a tendency to point your toes as you push off. Again, this just prolongs your ability to propel yourself forward and you can over stride this way.
So, focus on this. As soon as your foot strikes the ground, think about driving the knee forward. This is not a dramtic movement, but a subtle focus that keeps your foot dorsi-flexed (toes pulled towards your shin) and keeps you moving forward, quickly. This will also help you to activate your gluts to run. If you have the cadcence down, you are most likely doing great. What also helps is to try to spend as little time with each foot on the ground as possible. Strike, and then move the leg/knee forward, not up or back, pushing off.
Hope that helps - E