Yah, most of that is back east after hurricane Sandy and places in the Midwest that are pumping NG like crazy. I have gotten some wood dropped, but that has always been with loads of wood chips. Wood chips cost money to dump here (rip off recycling; they get money to take the chips and then sell the compost after processing it). So arborists are always advertising for places to drop loads of chips on CL for free.
I call them 'tree butchers' myself. On this forum site there used to be a lot of us pro arborists with chippers and such, and pro fallers. Now its guys with hopped up chainsaws boasting about wood cutting speeds cutting logs lashed to saw horses. As for firewood, no arbor business here that I know of sells firewood. Takes too much time and space. I do know a few that keep the wood to burn themselves, but most post ads on CL for free rounds to be taken on site. Then the wood zombies like me show up and it disappears in a few hours, especially better wood like oak. There are bigger firewood processors out here where I live where a lot of logging is done, and they buy and salvage cull logs that they haul and cut into firewood. Some sell it green to the suckers in the city. Some logging companies here sell cull logs direct to the public. A dumptruck load of green Doug fir & hemlock logs costs $300 delivered. They come to about 2.5 cords of wood bucked, split and stacked. You can also buy a logging truck load of logs for $1200, and that comes out to about 9 cords (roughly 3 cords per MBF, and roughly 3 MBF per logging truck: 1 MBF is a thousand board feet of lumber).
Failing is the path to knowledge and wisdom. I used to go after cottonwood here. No longer. I have a cord of Western Hemlock rounds here and a maul if you wanna give them a whack. I do not think there is any best tree ID book. I like Petersons field guide to western trees. There must be an eastern equivalent? Golden also has Trees of North America that has good drawings and maps of where stands occur. I also have several shrub and tree ID books that are local to the PNW that you would likely never find. No one book has all the trees that I have found and ID'd, especially old world species. For them I use Google.