There are a few things to get right when stacking wood. It's easy to do, if you keep the following guidelines in mind. Thinking things through ahead of time will not only lead to faster drying times, but also increase safety and eliminate nasty surprises.
The most important consideration when stacking wood is the stability of the stack. Safety must come first. Don't build your stack on your balcony or any other place from which the logs can fall. A single log dropped from that height can cause a lot of damage. The edge of a cliff, or the top of a hill are not good locations for the same reason. Use common sense. Don't let an innate piece of wood turn into a deadly missile due to bad planning.
On the ground interwoven ends secure stacks up to about 4ft in height. If you want to go higher, you will have to build permanent supports. Stacks higher than 4ft are also prone to being pushed over. These stack are only safe in dedicated structures made for storing large amounts of firewood.
Keep the stack dry
The stack has to be kept dry in order for the wood to turn into burnable logs. Leaving the stack uncovered and exposed to the elements will significantly slow down the drying process. A trap can be enough, if there is not too much wind driven rain. The spot under the overhang of a roof is an ideal place.
Temperature and humidity levels do affect drying time, but do not necessarily have to be controlled. Unless you live in the Amazon, any type of wood will eventually lose enough moisture. If your stack is in a controlled environment (indoors), the logs are going to dry faster.
Off the ground
It's imperative for the lowest rung of lumber to be off the ground. For starters, if the wood is in contact with the soil, it won't dry properly. The logs will probably never reach a moisture level low enough for during.
More importantly, dead, moist wood is the favorite food of termites. If you live in a termite region, which is pretty much everywhere in the US, stacking wood on the ground next to your house is akin to inviting termites into your home.
A frame built from two pressure treated 2x4s is enough to solve this problem. Even pressure treated lumber should not be in contact with the soil for too long. If you have cinder or cement blocks, place them under the frame. If you don't, plan on replacing the frame after a few seasons. It won't attract termites, but it will decay.
Clearance all around
For ventilation purposes the stack must have air circulating all around. This includes the front and the back. A common mistake is to stack firewood directly against the wall of a home. Besides increasing the drying time of the stack, the logs trap moisture up against the sheeting of the home. If there are any defects in the sheeting, the home will develop moisture problems.
Wood stack are also prime habitat for bugs. You will mostly encounter beetles and spiders, but the odd termite or carpenter might find it's way into the stack. If your stack touches your home, whatever lives in the stack is one step closer to the inside of your home. That should be enough motivation to leave an air gap between the back of the stack and the wall of your home. A foot will do.
When stacking wood it's best to think things through before doing the work. Site selection is paramount. Find a safe place somewhere out of the weather. Keep the wood off the ground, and allow for good air circulation. Your stack will turn into burnable wood within a season or two.