Working with wood is sometimes a necessity when upholstering.
I'll bet byhammerandhand has one of these. :D
http://i830.photobucket.com/albums/zz228/genejoe/8xaDw.jpg
gene
Yep, R. Bruce Hoadley has written one of the seminal works in woodworking, and is on the "ten must-have books" for any woodworker's library. http://www.amazon.com/Understanding-Wood-Craftsmans-Guide-Technology/dp/1561583588/ref=sr_1_1?ie=UTF8&qid=1358096362&sr=8-1&keywords=hoadley
I really get my geek on by reading: http://www.fpl.fs.fed.us/products/publications/several_pubs.php?grouping_id=100&header_id=p If you have a question about wood use, it's probably in there somewhere, in more detail than you can imagine.
Wood identification is an arcane art. People that do it seem to be like birders, they just enjoy the identification and classification. They delight not just in identifying "red oak," but which of the 35 species of red oak it is. Using a 10x magnifier to examine razor blade cut end grain is one of the primary techniques. So that's why the cover photo, no doubt.