Start up Nero, and when the New Compilation window comes up select DVD from the dropdown list, then select DVD-Video:

Press New to create the new project. Then you'll be presented with 2 windows, on the left you'll see the compilation, on the right you'll see a filebrowser much like Windows Explorer. Drag and drop the content of your VIDEO_TS directory on the harddisk to the VIDEO_TS directory on the DVD compilation.

Then press the burn button, select the write speed and press the Write button to start burning.