My water is fairly soft, and the water company publishes a typical analysis on the web. Although the analysis does vary a bit throughout the year, it isn't enough to worry about. Because I don't have too much of anything in the water, and I can achieve a good mash pH with some simple salt additions, I don't need to dilute with bottled water when brewing what I almost always brew (pale ales).
I then use EZ water calculator
http://www.ezwatercalculator.com/ to adjust the Ca, Cl, and SO4 ion concentrations to where I want them. According to the calculator, this always predicts a mash pH that is within range, and each time I have checked it with the pH meter, it has been OK. The only difficulty for me is to determine what concentrations of Ca, Cl, and SO4 I want. I spent years trying to figure this out before buying Pale Ales by Terry Foster, in which he gave some recommendations for various varieties of pale ales, and I have been following his recommendations ever since with good results.
For mashing, I start by pre-heating the MLT with hot water from the tap.
I then measure out the amount of mash water that I need, and start bringing it up to strike temperature in the kettle.
For most beers, I use 1 US qt water per lb grain, partly because this is traditional for English Pale Ales, and partly because it keeps the math simple. Using this mash thickness with English pale malt makes a very big difference to the character of the beer compared to using 1.25 qt per lb.
Having got the strike water heating, I go to the basement and grind my grains. Then I use EZ water calculator to calculate the amount of water salts to use for the mash, and weigh them out.
When the strike water is a few degrees over what Promash tells me I need, I drain the warming water from the MLT and add the strike water. I then wait till the strike water cools to the required temperature. (This usually takes 5 - 10 minutes).
Then I dump the grains and salts into the MLT and stir like crazy for about 5 minutes to break up the dough balls and thoroughly mix the grains with the water, check the temperature, and put the lid on the MLT. I then leave the mash alone for the next 90 minutes. (I usually mash at 150F, and have found that I don't always get full conversion in 60 minutes at that temperature with English base malts.)
During the mash, I heat up my sparge and mash out water, and measure out the water treatment salts for the boil. (I fly sparge, and find that a mash out increases my efficiency by about 10% with no detrimental effects).
At the end of the 90 minutes, I add the boiling mash out water, stir like crazy again, and wait for another 15 minutes before starting the sparge.
Can't help with march pumps, I use gravity.
Hope this helps,
-a.