i did take some lessons with Seattle Voice Lab (remotely) which i do highly recommend to folks if it's something they can afford. as far as free resources, my big thing is just to try and absorb a wide variety of stuff. the link you sent seems not bad, and transvoicelessons makes good vids.

more important than any particular resource though my advice is practice a lot, and *record* yourself practicing and listen back. try to focus on one aspect of the voice at a time (airflow, resonance, etc), push it to as far an extreme as you can to get a feel for it, *then* start combining things.