Tip 1 - Use the search feature, its amazing the number of people with the same problems.
Tip 2 - Update your console ( I believe its states in the manual you must do this before you can use the SD features - not 100% sure though).
Tip 3 - Although you can copy VC games and saves to the card, the Wii does not pick up the data in the channels or the games. It basically acts an archive, not useable storage.
Hope this helps