Unlike most structures a log won't obstruct movement.
One log will give 60 Woodblocks, or 30 or more Fresh Boards depending on the characters Hammer & Nail Proficiency if placed in a Sawbuck. Coffin Planks will also count towards the amount of Boards given. Chopping Woodblocks can only occur at one point on the side of the log, whereas making boards can be done from any side of the Sawbuck.
Logs can be relatively tricky to place, as they are put down extending outward from the character, in the direction the character is facing. The end with the point will be furthest from the player, and the chopping point for wood blocks will fall to the left side of the log, from the player character's point of view.
An immature tree will produce a smaller log containing fewer woodblocks and boards; or no log at all, if the tree is very young.
A log will turn into a Hollow Log if allowed to decay for long enough.