I can say that the manner in which you store your timbers does not need to be as elaborate as Jim descrihes. Typically, the system he describes is one which is often reserved for "Boards", which can't span large distances without deformation, rather than for Timbers, which can (depending on their dimensions).
I, and a great number of others, typically use three, or four, supports rather than supports every Two Feet, but, which are still, as Jim relates, as Level, and in Plane, as possible.
Some of what I have found helpful, in addition to the advice on Covering the Piles, and Using Dry Bunks in between Layers to minimize Sticker burn is
* Minimize Plant Growth up through, and around the Bases of the piles. For me enormous sheets of paper making Felt, and old, discarded paneling went down, first, under the Stacks, and served to inhibit weeds, grass, etc.
* Air Flow. One By stickers have always seemed to work MORE than fine with stacks of Boards, but, for stickering Timbers I rarely went smaller than Two Inches, and Often relied on Three Inch stickers. and tried to make my Piles a Maximum Width of Six Feet.
The thickness of the Stickers helps to facilitate that Airflow Jim and the others mention, as well as allowing for Forks to be used to pull the piles apart, if needed. (If the Timbers are stacked Level on an unlevel surface, and the Timber Handling Equipment is unable to pivot it's forks, thicker Stickers will be of enormous help here).
If each stick that goes into a Pile is Done, and the Barn is to be transported to another site for erection, then create your stacks with Loading in mind. This will allow you to rapidly load your frame when the time has come (Something to think about, not neccesarily something to live by).
Three months is a Very short period. Airflow and a good, level Bed, as high up from grade as you can Reasonably get, will be the only truely Crucial elements (and end grain sealer). But, I have had Frames in the yard that Should have gone out in three to four months, become delayed and delayed, and delayed, for one reason or another, so, for me, I got into the habit of stacking as though the timbers would need to sit through multiple Summers. It's not a bad practice to get into.
Tim Berube