I just started AG brewing and have been using recipes that have all the information I need to brew. I just bought all my ingredients for a christmas porter and just noticed no info for mash temps amt of water, and sparge temp and amt of water.
As a rule of thumb, I mash with 1.25 qt/lb of grain (for mash in I have an extra .25 qt/lb heated to boiling and the same amount cold in the fridge. This gives me .25 qt/lb either way to make adjustments if I miss my mash temp) and 2 qts per pound of grain for sparge. Mash temperature for a porter I would shoot for 152-154.
So a ten pound batch would have three gallons of mash water (12 quarts) with an extra 2.5 quarts just off a boil and another 2.5 quarts set aside in the fridge. Then sparge with 5 gallons (20 quarts).