Though the url for this site has been posted before, it's worth posting again. If you've got a chunk of wood and want to find out what it is - THIS IS A GREAT PLACE TO START!
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Lots of color photos, often with close ups, especially of end grain, cross referenced "common names" to latin names, critical if you want to find technical info on a particular wood. And for folks who want photos of their work - that actually look like the real piece - no added blues or reds because of lighting etc., there's info on how to get photos with accurate colors - including computer monitors and colors, digital cameras and color correction, info on wood toxicity etc..
Bookmark this site - with asterikses (sp?) - it's a keeper you'll use often - especially if you're a wood phreak.
charlie b