How to tell seasoned wood.
Bark comes away easily and cracks can be seen in the ends. This is important as the calorific value of 'green' unseasoned wood is very low compared to seasoned wood.
The moisture content of seasoned wood should be between 18-25%. Unseasoned 'green' firewood can be 50%-60% or more.
'Seasoned' wood can provide up to double the heat energy output in the firewood as opposed to unseasoned 'green' wood.
It's better to buy wood by volume rather than by weight or you could be buying wet wood.