Bill Hilton
http://www.billspianopages.com/
A very good teacher with a lot of free material on YouTube. His teaching style is relaxed and covers all levels. His books are very good as well.
Improvpianotips from Nikolas Nuñez
Another very good teacher. He has free YouTube content, a free course on his site for beginners and paid tuition. Well worth registering for his free lessons if you are a beginner. I’m halfway through his “rhythm techniques for you” package. I will review this once I’ve completed the course.
Check out the video below to sample his tips on improvising…
Pianoworld
A huge forum for everything piano. If you require a piano tuner, advice on buying a piano, learning techniques amongst many others, you will find it here. Well worth a visit.