We have a Japanese Wii. We can read some Japanese but it’s annoying to navigate through all the menu items with our lousy Japanese.
So, the Goonfather got fed up and started taking screenshots of all the menus and went searching through the Nintendo manual for the English versions to compare with. And the result of his labour is this 28-page pdf document with translations and a guide on customising all sorts of settings!
And if it helps you, thank the Goonfather!