May want to try Laura Stamm's book or DVD, Power Skating.
Bending your knees helps to add power, you should have them near 90 degrees while skating. Another thing that helped for me is to keep your weight near the heel of your feet skating forwards and the ball of your foot skating backwards. And make sure your skates are tied tight enough that they aren't sliding around.
Beyond that, just lots of practice on every edge in both directions.
take full strides touch those skates to you butt is what coaches taught me that little extra in that stride really does help. also make sure you have sharp edges on your skates if your not good at skating it does help to keep a edge when you turn. sometimes also go to your local rink and see if they have like open ice or free skate and go there it helped me when i was learning when i was a kid.