Distance: This works for me:
add/subtract 1 foot for each inch the putt goes uphill/downhill.
Take that number and divide by:
.9 for slow greens
1.0 for standard
1.1 for fast
1.2 for very fast
1.3 for tournament
And use the result as your putting distance. However, inside 10' is different, usually you will want to hit it somewhat harder, and inside of 3' you can usually ram the ball in, perhaps aim slightly to the right or left depending on the severity of the break.
There are two basic methods for how far to move the meter. The percentage method and the avatar movement method. There are some formulas for the percentage method (what % to move the meter) floating around if you do a search, but I use the avatar movement method.
The avatar movemnet method consists of seeing how many times your avatar draws back the putter for each scale and converting that to feet, for example 2 1/2 times for 15' scale = 6-6-3 feet, 5 times for 30' = 6-6-6-6-6 feet. Using the number you calculate above move the avatar the appropriate amount.
But I think that relatively easy compared to reading anything but a slight break. That just comes from playing a lot.
There are also some rather longish and complex formulas floating around for distance and breaks if you do a search, but the math above is about as far as I want to go, it is a matter of personal preference.
Sources:
http://www.wgt.com/forums/p/89159/565243.aspx#565243
http://www.wgt.com/forums/p/22186/126517.aspx#126517