I know it is far from scientific-and I'm a relative N00b to AG, but I've had success with the following general procedure:
-Heat up about 4 gallons of water to 170
-Dough in the water to the grain, stirring to make sure there's no lumps or dry pockets. Add a little grain, then a little water and repeat until it's the consistency of oatmeal (not too thick or too thin).
-Take the temp from various parts of the mash. If it's closer to 150-it'll finish more dry...closer to 160 it'll finish more sweet.
-Add hot or cold water to reach desired mash temp and close mash tun and let sit for 60-90 min.
I sparge until I have 6.5 gallons, and boil for an hour or until it gets down to 5.5 gallons (tends to boil off at a gallon an hour-or close to it).
That's the layman's terms...I know there are more precise ways, but the monks and the Egyptians never had any software either.