You're going to have to figure that out for yourself and your shooting style. I use a combination of all of those settings depending on what I want to do. If you have used any other Nikons in the past, they are the same controls you have switched in the menu settings.
Personally, for sports, I use the auto focus buttons and the general area (I don't know what they call it in the manual but it's the one where there are 4 focal areas) because I don't have the time sometimes to set up on those shots. For weddings, portraits and pretty much everything else, I don't think you need an auto focus because your shutter release will focus when it's halfway pressed (just like normal) and I just use the single focal point area.
Have fun with it. It is a great camera.