“CGTextures strives to be the worlds best texture site. Being a 3D artist myself, I know how hard it is to create textures without good photo materials. Making textures should be about creativity, not about spending hours looking for the right image on the internet. I hope that by supplying good quality textures in an organized manner, your everyday work will be easier and more enjoyable.”
That’s what the owner of CG Textures states. Trust me. They have some great wood textures :D
cgtextures is a great site, but not so hard to find. A rather unknown but great site with textures is http://www.YourDailyTexture.com
The Textures are all seamless and high res. You don´t find this combination very often.