I made this wood shader for handling multiple objects of like-cut wood, such as these Jenga-style blocks:
It is accomplished by applying a noise texture to the UV vector using an “Image Mix” node. Details on this specific technique can be found here:
Greg Zaal’s blog is a GREAT source of information.
In my case, the Object Info “Random” output is fed into the Distortion parameter of a plain-jane "“Noise Texture” node. It is further added to the base texture UV vector using “Vector Math” in so that the grains do not line up.
I was pretty surprised how well it worked.
Here is the setup for the texture mapping section:
I have also included the blend file, but I do not have distribution rights for the wood texture itself, but can be found herefrom the publisher. Any wood should work with tweaking.