Hi WAS,
PGMusic sells some great software learning aids.
I recommend the Blues Pianist, the Master Piano Class, the Modern Jazz Pianist, The Oscar Peterson Multimedia CD and there are others as well.
These interactive programs are like having private teachers at your beck and call 24/7 -- and the ability to repeat any lesson on an as-needed basis.
No kidding, for the entry price you can't get a live teacher and these programs are in many ways actually better than a live teacher in that you can proceed at your own pace, whether fast or slow, they do indeed teach the things that are needed to know in order to become a good all around improvisational style pianist and all of them start out with the slow and easy and accessible, gradually increasing in depth until you are dealing with university level situation.
I recommend the Blues Pianist as the perfect starting point. Starts with rather simple and easy LH boogie patterns. The Blues should be the underlying basis for any and all improvisational piano styles IMO.
The softwares can be viewed at the hotlink below:
http://www.pgmusic.com/products.win.htm --Mac