"They show that if the hydrogen is present as water ice, then the average concentration in some craters corresponds to ten grams of ice in each kilogram of moon rock.
...
If the hydrogen is present as water ice then our results imply that the top metre of the moon holds about enough water to fill up Kielder Water.”

Kielder Water, in Northumberland, holds 200,000 million litres of water, making it the largest UK manmade reservoir in Northern Europe."
http://www.sciencedaily.com/releases/2008/12/081217192743.htm

Or 1/5th of a billion tonnes.

If the best concentration of water on the Moon is 10 grams of ice per kg or about 2%
per volume, it's not particularly promising in terms of being minable.
In terms extracting the water how much of the 10 grams per kg of regolith could you reasonably extract?