Good links!
I've Recently been pushing Reece to my back in the sling when I need to prepare food, or when I'm packing groceries at the grocery store or folding laundry. I use the back carry for brief periods of time only.
Basically I put baby in the sling as I normally would in a hip carry, placed as close to my arm as I can get him (I make SURE his knees are slightly higher than his butt and fabric pulled right under his knees and all the way up to his neck, arms tucked in.. I also place the rings higher on my shoulder than usual) Then, I make sure I tighten the fabric so baby REALLY snug (even more snug than usual), then my arm that's behind baby- I lift over his head, cross my chest and grab the shoulder of the sling. With my other hand I reach behind myself to grab his bum. With one hand on the shoulder of the sling and the other on his bun, I slide him around to my back.
HTH