Nintendo.com has the official user manuals for the Wii, as of August 2015. The website provides the manuals in PDF format and offers the French and Spanish translated versions.
From the Nintendo website homepage, click on Support in the navigation bar. If prompted to choose a region, select English under U.S. & Canada. Click on Product Manuals under Documents / Policies in the footer of the page, and then click on the Wii, Wii Mini or Wii U button. Choose the manual from the list, and then click on either the English, Français or Español link. Depending on browser options, the manual is viewed from a browser or downloaded to a hard drive.