Burn Only Seasoned Wood
Seasoned wood usually contains 20 - 25% moisture content, while unseasoned wood can have up to 45% water content. Seasoned firewood is easier to start and produces more heat. In order to make sure that you are purchasing seasoned wood, buy it in the summer 6 months before you plan to use it. Green wood or unseasoned wood must dry out before it will burn properly. Burning green wood can cause smoking problems, odor problems, creosote buildup and possibly dangerous chimney fires.

How to recognize seasoned wood when you see it
With a bit of practice you can learn to recognize seasoned wood when you see it. One sign is that the bark has loosened its hold, or has already been knocked off with handling. Also, the log ends have darkened, dried out and started to crack.

A well seasoned firelog will be lighter in weight than an unseasoned or green piece of the same size and species. When it really is well seasoned, expect to pay more. Cutting trees down, transporting, handling and working up wood is a risky, labor-intensive pursuit. The more times a supplier has to handle it, and the longer he ties up space storing it, the more he will charge.

Storing Firewood
Store wood off the ground in a location away from the house because termites will be looking for it. You can easily make a place to hold the wood by placing two 2x4s or 2x6s parallel to eachother on the ground. Stack wood across these boards, then cover with a tarp to protect it from the elements.

Buying Firewood
Firewood is generally sold by volume, the most common measure being the cord. A standard cord of firewood is 128 cubic feet of wood, measured as a stacked pile of wood 8 feet long by 4 feet tall by 4 feet deep.

Although firewood is usually sold by volume, heat production is dependent on weight. Pound for pound, all wood has approximately the same BTU content, but a cord of seasoned hardwood weighs about twice as much as the same volume of softwood because it is denser. It contains almost twice as much potential heat and this means that you will have to load your fireplace less often if you purchase hardwood, but it is certainly find to use soft woods. Mixed wood (soft & hard wood) by the cord or 1/2 cord is a good buy. Use the softwood to get the fire started and then add the hardwood for a nice long burn.

Never burn any construction scraps of treated or painted wood, especially treated wood from decks or landscaping ties. The chemicals used can release dangerous amounts of arsenic and other toxic compounds into your house. Never burn plastic because it releases toxic chemicals. Never burn large amounts of paper (use your shredder). As for Christmas trees, I know it's tempting but don't do It!