let sit or start cutting?

[kkcomp]

In the area I am building a house the following trees that need removed have been identified: Willow Oak, Swamp Chestnut Oak, White Oak, Shaggy Bark Hickory and Red Pine. Should I let them sit a while before milling or mill right away?

[Magicman]

I prefer to saw logs as soon as possible after felling.

[Ianab]

There are some exceptions, but most logs saw better when fresh. Then you can get them stacked and drying before problems like bugs / rot / end splitting set in. 

How long logs last once down also depends on the species / climate / season etc. Some of the more durable woods can be OK after years on the ground, others start to stain and get bug eaten in weeks over summer.