All my meshes & textures are extracted, but when I pull up a mesh in nifscope it's solid white. Do I have to assign a directory for the textures or something?

Yep. There's a Settings menu - under 'File' I think. It doesn'r auto detect Skyrim, but you can put the path in by hand.

[edit]
My mistake, 'Settings' is under 'Render'.

Thanks. That did it!