Sigidi,
Having timber delivered to your home for your own use is normally within the confines of the laws in residential areas, what gets you in trouble is having it delivered, processing it then reselling it, then you can be potentially considered industrial, or commercial for the manufacture and or resale.
When receiving timber from a contractor the determination should be made that the contractor is removing the timber based on the contracted requirements and not selling standing timber that would otherwise be the property of the landowner. It could be argued that if there is any profit to be gained that the property owner should ultimately receive the gain as the true owner, however if the owner contracted to have the area landscaped and those trees removed, it then becomes a factor of the contract. The contractor could have bid the job based on a resale of the timber value or the cost of the disposal of the waste (timber). I would recommend that if there is any question that a written contract for the timber sale or split for sawing is complete before pulling equipment on site or removing stock.
I failed to mention earlier, that if I don't go for the 50/50 split of lumber for free logs. I have done that in the past especially when I first got started. But I have found that if you don't have a dry place to wharehouse the lumber you are ultimately in a loosing battle. Poor looking lumber that has been out in the weather for 6 months dosn't have the sale value that bright lumber fresh off the mill has. I try to keep an assortment of logs on hand rather than an assortment of lumber. Its easier to keep the right inventory, and my inventory can support any of several different cut requirements when still in the log form but you won't get a 2x6 out of 2x4 in the near future.
Last comment.... Always take care of your sources, If a contractor, tree service or utility company routinely comes your way with free timber, keep them on your phone list, and give them a call see if they need any lumber for local projects. IF they show with a big order give them a substantial discount, if they need a few boards for a project make it a freebe.
Eric