Much of the information is in other posts so I'll summarise from best picture I have found down.
BV7-40 MK11
The Component section above the DVI socket, then the left and right channels on rear of the BV7 (AV4).
Wii Scart RGB cable, it carries sound as well. (these are not fully wired, so will not turn the TV on).
A Scart to RGB adapter, then use a Wii RGB cable or possibly component cable
Standard Wii composite cable connected to the Camera input using the left and right audio channels. This is the easiest mode to start with and the games look better than the Wii Menu's.
SVideo sits between the 3rd and 4th option.
Feel free to correct.
Not sure how the BV7-MKIII handles this..
beoaus.