Yay! We've reached the burning process!
Open up ImgBurn(The program you installed earlier) and select "Write image file to disc".
If your using a mac you can just use disk utility to burn it. Again there's a short guide
here
Near the top there will now be a small icon beside the text saying "Please select a file".
Choose the first small icon with the little folder and magnifying glass. A windows will pop up and ask you to select a file. Select the file we copied from the wii earlier or if you downloaded the game select where you downloaded it to and press open.
Now insert a disk. At the right bottom corner there will be a settings panel.
Set the write speed to the half of what the disc you bought is rated for(E.g if you bought a dvd rated for 16x
put the write speed as 8x). Some older burners give best quality burns at lower speeds like 4x but it's best to experiment to find out the best speed for your burner.
If you are burning a dual layer game(The only current game that uses a dual layer disk is SSBB) make sure that you have a dual layer disk inserted and do the following:
Go to >Tools>Settings>Write>Layer Break>User Specified in imgburn and type 2084960
You're ready to burn the disc! But first exit out of all programs currently running(It helps in making the dvd's good quality). Now press the big write button at the bottom of the window.
This will take less than thirty minutes depending on what speed you chose.