hai gia' cercato su google?
http://www.google.com/search?client=...utf-8&oe=utf-8

tra i link proposti:
a pagamento:
http://italiano.istockphoto.com/file...&SearchLang=IT
http://www.fotosearch.com/photos-ima...ures-wood.html

free:
http://www.pixelpoke.com/ornament%20thumbnails.htm
http://www.pixelperfectdigital.com/f...ry.php/cat/532
http://www.alterlinks.com/textures/c...id=wood&page=1