I have been working with a very qualified instructor on two areas of my weakness (reading and tech) so she has changed my hand positioning to the ideal position for a nice legato tone.
I am sure xvimbi will join in in a moment.
Get a copy of the book "What every pianist needs to know about the body" by Thomas Mark. Check out www.pianomap.com for starters. I have yet to see a better text.
Xvimbi, would you also recommend Mark's video?
don't expect full-fledged instructions in piano technique. The Taubman videos will cover that.