When you reach 20 level (Baa-rvester), the Log Cabin becomes available in the Pondsville. You can perform various quests there. The Forestry (in Pondsville, on the the top of the hill on the right) becomes available when the 3d quest is completed. First you can plant common spruce. Then, with completing the quests, silver birch, beech and poplar would be also available for planting. After 6th quest completing the Sawmill becomes available, where you can produce planks, scantling and roundwood from logs. Later you can produce different wooden items from this timber in Carpentry (available after 12th quest completing).
There could be up to 3 production slots in Sawmill and Carpentry. First slot is available just after Sawmill construction, the second could be bought for 1 800 000 pD, - these two slots are constantly available. The third is time-constrained production slot can be rented for 48 hours for 5 Coins.
Two customers visit your forestry every day and present their shopping lists. You can get both pD and points for selling the goods for these customers.
Here are the types of products of Sawmill and Carpentry, as well as the expansions for these buildings.