One caution: many people get into the excitement of a supply of free wood and end up with much or most of it wasted, ending up that it would have been cheaper to buy the lumber. I think it is important to research this well before committing.
There is a lot of info on the internet about successfully air drying for research. There are also useful government publications. If you have enough wood, it might be profitable to pay for kiln drying.
Don't forget handling and hauling large amounts of wet wood, preventing insect damage, cost of the support system and stickers, sufficient space for having stacks of stickered lumber around for years, and storage space for the dried lumber.
BTW, 1 year per inch is a very rough suggestion which makes a lot of assumption, not even close to reality in many cases. The typical rule-of-thumb is actually 1" per year PLUS one year. Even this falls apart in reality with certain species (white vs red oak vs cherry, walnut, etc), thicker timbers, untypical environmental conditions, poor handling.
I have a sawmill myself but I usually cut wood into woodturning blanks. When I do cut boards for air drying i use methods to measure the moisture instead of relying on a rule-of-thumb.
JKJ